[7] Five days later, on 28 April 2005, Vlaar made his European debut when he was part of the starting line-up in the UEFA Cup semi-final away match against Sporting Lisbon, losing 2–1.

"[22] After being given a number twenty shirt, Vlaar made his official Feyenoord debut on 15 January 2006, in the away match against Vitesse Arnhem, as the club won 1–0.

With the arrival of the new Feyenoord coach Bert van Marwijk and new centre back partner Kevin Hofland in the 2007–08 season, Vlaar was ready to make the next step in his development.

"[57] After being sidelined for two seasons, Vlaar made his return from injury, appearing in a number of friendly matches in Feyenoord's pre–season, as he was making his progress on regaining his fitness to fight for his place in the first team.

[86] Vlaar was among thirteen players to lose confidence in Mario Been, prompting him to resign as Manager of Feyenoord, leading Ronald Koeman being appointed as Been's successor.

"[90] Later in the 2011–12 season, Vlaar played a key role in reaching second place in the Eredivisie with the club, securing a spot in the third qualifying round of the 2012–13 UEFA Champions League.

[96] Vlaar responded to the transfer speculation, while facing uncertainties over his future with Feyenoord, he wanted to stay at the club and helped them win the league ahead of the new season.

[97] On 15 July 2012, Feyenoord confirmed that Vlaar had travelled to Birmingham to hold talks with Aston Villa manager Paul Lambert with a view to a possible transfer.

[100] In another turn of events, it was then announced on 27 July that Vlaar would eventually be joining the Premier League side, as he had agreed personal terms and would sign for Villa subject to him passing a medical.

[102] Shortly after joining Aston Villa and was given a number four shirt, Vlaar spoke out on the club's website about his adapting in the country and aim to be a cult hero among supporters.

[113] Following his return from injury, Vlaar regained his first team place for the rest of the 2012–13 season, forming a partnership with Clark and helping Aston Villa fight for survival to avoid relegation in the Premier League.

[126] After being on the sidelines for ten days with the injury, Vlaar returned to the starting line–up against Cardiff CIty on 11 February 2014 and helped the club keep a clean sheet, in a 0–0 draw.

[142] In response, Manager Lambert said Aston Villa will not sell Vlaar in the January transfer window, which, he agreed and announcing his intention to see out his contract.

[143] Vlaar made his return to the starting line–up against Leicester City in the fifth round of the FA Cup on 15 February 2015 and set up the first goal of the game, in a 2–1 win.

[147] Vlaar then relinquished his captaincy role to Fabian Delph for the rest of the 2014–15 season and played his first match without an armband, in a 2–1 win against Liverpool in the semi–finals of the FA Cup.

[148] Following this, he formed a central defence partnership with Jores Okore and the pair even played together in the 2015 FA Cup Final at Wembley Stadium, where the team were defeated 4–0 by Arsenal on 30 May 2015.

[174] A week later on 3 November 2016, he made his return to the starting line–up against Maccabi Tel Aviv in the UEFA Europa League and helped the club keep a clean sheet, in a 0–0 draw.

[176] After being out for two months, it wasn't until on 23 February 2017 when he returned to the starting line–up against Lyon in the second leg of the UEFA Europa League Round of 32 and played the whole game, as AZ Alkmaar lost 7–1 and was out of the tournament.

[177] Following this, Vlaar regained his first team place, playing in the centre–back position, competing with Rens van Eijden and Luckassen, as well as, retaining his captaincy, but he faced his fitness along the way.

"[188] Vlaar returned to the duty as captain when he made his first starts in six months against ADO Den Haag on 31 March 2018 and helped the club keep a clean sheet, in a 3–0 win.

[199] But Vlaar made his return to the first team from injury, starting a match and playing 57 minutes before being substituted, in a 2–2 draw against PEC Zwolle on 30 September 2018.

[205] The club's six consecutive clean sheets ended against Willem II on 24 February 2019 when Vlaar and Marco Bizot had a miscommunication, resulting in Marios Vrousai capitalising the mistakes to score, as AZ Alkmaar lost 2–1.

[213] After missing one match due to his fitness concern, he played in both legs of the UEFA Europa League play–offs round against Royal Antwerp, as AZ Alkmaar won 6–2 on aggregate.

[231] After beating Chile U20 (3–0) in the next round, the Netherlands U20 reached the quarter-finals against later finalist Nigeria U20, which they lost 10–9 on penalty shootout following a 1–1 draw at Extra time.

[238] Jong Oranje started and finished their campaign against Ukraine U21, going out on a high with a 3–0 win in the final, after surprisingly losing their opening game to the Ukrainian team.

[244] He had to leave the pitch injured in the semi-final match against England U21, as the U21 national team won 13–12 on penalty shootout following a 1–1 draw at extra time).

"[251] In the few matches the promising defender played, Vlaar made enough of an impression to be noticed by Marco van Basten, the coach of the Netherlands national team.

[253] A month later on 12 November 2005, he made another appearance for the senior national team, starting a match and playing 60 minutes before being substituted, in a 3–1 loss against Italy.

[271] After being dropped to the substitute bench in the next match against Germany, he returned to the starting line–up against Portugal, as the national team lost 2–1 on 17 June 2012, resulting in them finishing bottom of their group.

"[273] Following the end of the UEFA Euro tournament, Vlaar was Louis van Gaal's first-choice centre–back for Netherlands for FIFA World Cup qualification Group D matches for the rest of 2012.