Nicholas Alexander Leendert Vlastuin (; born 19 April 1994) is a professional Australian rules footballer playing for the Richmond Football Club in the Australian Football League (AFL). He is a three-time premiership player with the club, winning in 2017, 2019 and 2020. He plays as a hybrid defender, adept at directly defending small forwards, taking intercepting marks and rebounding from defensive

Early life and junior football Vlastuin spent his formative years living in Eltham North, a suburb in Melbourne's north-east. He played his junior football at Eltham in the Northern Football League before moving to the Northern Knights in the TAC Cup at the age of 14.

In 2011 Vlastuin represented the premiership winning Victorian Metro side at the Under-18 National championships. He returned to the team in 2012, this time captaining the side to the competition title. He was also named All-Australian for his performances in the tournament.Phelan, Jason (2012). Top teams dominate Under-18s All Australian side – Australian Football League. Published 6 July 2012. Retrieved 6 July 2012. As an Under-18 player Vlastuin was also a member of the AFL-AIS academy; an elite training program for 30 of the country's best young footballers.

Vlastuin completed high school at St Helena Secondary College in 2011. In addition to football commitments, he worked as a pool lifeguard during 2012.

AFL career 2013 season Vlastuin was drafted with 's first pick and the ninth selection overall in the 2012 AFL Draft .

Vlastuin made his AFL debut in round 5 of the 2013 AFL season in an away game against Fremantle at Subiaco Oval. In round 7 of the same season he was nominated for the 2013 AFL Rising Star after a 23 possession game against Port Adelaide. He also kicked his first career goal in the match. He would go on to play 18 games in his first season, recording an average of 16.3 disposals and 4.8 marks per game and placing sixth in the Rising Star award. In addition he received the Cosgrove–Jenkins Award as the club's best first-year player.

2014 season Vlastuin began 2014 in the club's best-22, playing in round one against . In fact, he played in each of the club's first seven matches before suffering a broken finger in round 9 against . He would return to football relatively quickly however, missing just two rounds of AFL action. Between rounds 15 and 18 he was prolific floating forward, kicking a goal in each of the three matches. He finished the season having played 20 matches at AFL level, including a finals series appearance for the second straight season. Vlastuin placed seventh at the club for tackles and ninth for rebound 50s in 2014.

2015 season In his third year at the club, Vlastuin managed to play in all 23 possible matches. He recorded double digit possessions in every match in 2015 and finished top-ten at the club for tackles and rebound 50s. He placed sixth in the club's best-and-fairest award, his highest place to date. He was also nominated for the AFLPA's 22 Under 22 team but would fail to make the final team. At season's end he underwent minor hip surgery.

2016 season At the beginning of the 2016 season, Vlastuin adopted the #1 guernsey, worn the previous year by retiring former club captain and personal backline mentor, Chris Newman. In an under strength side for the club's first pre-season tournament match he played the role of captain, despite not being a member of the club's leadership group. He played in each of the club's first four matches that season before a leg injury kept him out of action for two matches. Upon his return in round 7 he took on a midfield role, replacing the injured Trent Cotchin. He recorded 16 disposals, six tackles and a goal in the match but did not reprise the role on a regular basis that season. Vlastuin suffered a concussion in the second quarter of the club's round 11 loss to . In addition to missing the remainder of the match he sat out two more games, not returning until after the bye, in a round 14 match against . From that point forward he did not miss a match, finishing the season having played 19 games in 2016. He was again nominated to the 22 Under 22 squad that season but would go unselected for the second straight season. He placed ninth in the club's best and fairest count in 2016.

2017 season

Prior to the 2017 season, Richmond's coaches pegged Vlastuin for a move to a more stoppage focused role. He ceased training with the club's backline specific group and moved into the club's midfield training group. Vlastuin was a key member of Richmond's strong start to the 2017 season, playing in the club's round 1 victory over Carlton. He kicked a goal during the match while his 12 tackles for the match set a career best. Vlastuin suffered a broken nose and concussion in the club's round 3 win over . He played with the lingering effects of the injury in round 4 before concussion symptoms saw him sit out the club's round 5 match against . Vlastuin suffered a shoulder injury in the second quarter of his side's round 7 match against the . Scans later revealed a small scapula fracture with initial estimations suggesting he would miss three to four weeks of play. He ultimately missed more than two months of AFL football, returning to the club's senior side in round 17 following a fortnight of matches in the VFL. He would however return to his previous home in the backline, with his midfield move scuttled by his injury, by previous injuries to key backline personnel and by the emergence of young midfielder Jack Graham. Vlastuin was back to his best in that role, lifting his metres gained average from 20th at the club to third as well as his intercept possession count from 1.8 to 8.3, good for ninth in the whole league. In round 18 he was among the Tigers' best, recording 11 marks and 21 possessions (including 13 intercept possessions) in the club's win over the GWS Giants. He held his form into the finals series, playing a "pivotal" role in Richmond's qualifying final win over Geelong. When Vlastuin and the Tigers won over in the preliminary final, he was lined up to defend 's Eddie Betts in the grand final. Vlastuin started slow, giving up a goal to Betts early in the first quarter. He turned his performance around however and contributed 16 possessions and six rebound 50s to Richmond's first premiership winning side in 37 years. He played 16 matches that season and finished 2017 as a premiership player.

2018 season

After playing well in each of Richmond's two 2018 pre-season matches, Vlastuin contributed 12 disposals in the club's season-opening win over Carlton. He suffered a delayed concussion from that match however, forcing him to miss round 2's grand final re-match with . Vlastuin returned after just one match on the sidelines but was handed a $2,000 fine for a rough conduct charge picked up during that round 3 win over . Two weeks later Vlastuin was ruled out of the club's round 5 ANZAC Day eve match against with a minor calf strain. He again missed just a single match, returning to play his 100th career match in round 6's win over . After season-best totals of 26 disposals and 12 marks against in round 8, Vlastuin ranked second at Richmond for intercept possessions with an average of 7.5 per game. In round 10 Vlastuin was forced to play the second half of a match against as a forward after Richmond full-forward Jack Riewoldt sustained a concussion mid-match. Vlastuin performed strongly in the role, kicking an equal career-best three goals. In round 13's win over , Vlastuin was named among the best players on the ground by AFL Media and the Australian Associated Press and received best on ground honours from the coaches with nine votes in the coaches association award following a 21 disposal and 11 mark performance. To that point he ranked 14th in the league for intercepts per game. Following the bye Vlastuin was again prolific, notching 21 disposals, 10 marks, a goal and six coaches votes that also saw him named in AFL Media'''s Team of the Week. However, he also attracted a one match suspension for an elbow to the face of midfielder Luke Parker that saw him miss one match in round 16. At the beginning of August Fox Footy analyst David King labelled Vlastuin "a Luke Hodge clone" and the "AFL's most prolific intercept marker across the half-back flank (in 2018)". Vlastuin closed out the home and away season with wins in each of Richmond's last six matches that saw the club finish as minor premiers. Despite being unselected in the league's All-Australian squad, Vlastuin was named to the best 22 in The Age chief football reporter Jake Niall's team of the year, "in recognition of his rise to become an elite backman". Richmond opened the finals series with a qualifying final victory over where Vlastuin was identified by AFL Media as a key part of his club's "almost impassable" defence. His finals run would extend just one more match however, when Richmond was eliminated with a shock preliminary final loss to rivals . Following the conclusion of the 2018 finals series, Vlastuin was named as a close miss by the Herald Sun's chief football writer Mark Robinson in his list of the 50 best players from the 2018 season. After 21 matches and new career highs in marks and disposals per game, Vlastuin placed eighth in the club's best and fairest award.

2019 season