Thomas Vermaelen (born 14 November 1985) is a Belgian professional footballer who plays as a centre-back for Italian club Roma on loan from Barcelona. He also plays for the Belgium national team. Being left-footed, he usually plays as a left-sided centre-back and can play at left-back as well. His key attributes include aerial ability, leadership skills, and his quickness with the ball at his feet. He is also known for his goalscoring ability as a defender.
Vermaelen started his youth career in his home country with Germinal Ekeren, which later became Germinal Beerschot after a merger.
Vermaelen joined the academy of Dutch club Ajax. He made his professional debut on 15 February 2004 in a 0–2 away win over FC Volendam.
His breakthrough came when he returned to Ajax and won the KNVB Cup. Performances that season resulted in a call-up to the Belgium national football team. Ajax won the Johan Cruyff Shield and another KNVB Cup the following season and in 2007, they won the Johan Cruyff Shield for the second consecutive time. He forged a partnership with fellow academy graduate John Heitinga and later Jan Vertonghen when Heitinga left for Atlético Madrid in Spain. Following the departure of Klaas-Jan Huntelaar in mid-season, Vermaelen served as captain of Ajax for the remainder of the 2008–09 season, and he played mostly as a left-back.
Vermaelen joined Arsenal from Ajax for an initial fee of €10 million (rising to €12 million) on 19 June 2009, signing a four-year contract. After Kolo Touré surrendered the number 5 jersey to him upon joining Manchester City, Vermaelen, with William Gallas, formed Arsenal’s central defence pairing. Vermaelen made his Premier League debut on 15 August 2009 in a 1–6 away win against Everton, and scored in the 37th minute. He became the 84th Arsenal player to score in their debut. He then scored a brace against Wigan Athletic in a 4–0 victory.
Arsenal fans voted him as their Player of the Month twice in a row on Arsenal.com, and affectionately nicknamed him the “Verminator”. He scored an own goal, however, in a home match against Chelsea when a cross came in from Ashley Cole. The game finished 0–3 to Chelsea at the Emirates Stadium.
On 9 August 2014, Arsenal accepted a £15 million offer from Barcelona for Vermaelen. The next day, he completed his move after signing a five-year contract. Vermaelen was plagued with injuries since his transfer; he was thought to be ready for Barcelona’s game against APOEL in the Champions League, but was taken out of the squad. He underwent surgery on 2 December 2014 for a recurring hamstring injury, and was expected back in four-to-six months. After being an unused substitute in a 2–0 win over Real Sociedad two weeks earlier, Vermaelen started on his debut for Barcelona on 23 May 2015 in the final La Liga match of the season against Deportivo de La Coruña in which he played for 63 minutes before being substituted for Douglas in a 2–2 draw at the Camp Nou.
In the second game of his second season on 29 August 2015, Vermaelen scored his first goal for Barcelona, finishing a corner kick to win a home match against Málaga. He was praised by manager Luis Enrique afterwards. Vermaelen was an 81st-minute substitute for Javier Mascherano on 20 December as Barcelona won the 2015 FIFA Club World Cup Final against River Plate in Japan.
On 8 August 2016, Roma loaned Vermaelen from Barcelona on a one-year deal with an option to purchase.
Vermaelen made his international debut for Belgium in 2006, and has gone on to win 58 caps for his country. He represented them at the 2008 Olympics where they came fourth, at the 2014 FIFA World Cup and UEFA Euro 2016.