Vitesse Born in
Gendt,
Gelderland, Schaars was first discovered by Dutch coach
Theo Bos, who went on to manage Schaars' U13 Vitesse youth team. Following successful development in Vitesse's youth team, he was promoted to the main squad for the final few games of the
2002–03 Eredivisie. He made his debut for the club on 9 March 2003 in a 4–1 away defeat to
FC Utrecht. The following season he became a regular in Vitesse's side at the age of 19. In his first full season he played 21 league games. In the
2004–05 Eredivisie, he helped his club reach a credible seventh place in the league contributing four goals in 21 appearances.
AZ In the summer of 2005, he was signed by
AZ. In his first full season at AZ, he suffered a serious hip injury at the beginning of the
2005–06 Eredivisie season which kept him out for several months. He returned in February 2006 against
FC Utrecht in a 2–3 defeat. In the next season he missed most of it due to sustaining a number of serious injuries which also kept him out for the
2007–08 Eredivisie season. His return came in the
2008–09 Eredivisie season, where he played a pivotal role in midfield along with
David Mendes da Silva,
Demy de Zeeuw and
Maarten Martens to claim AZ's second league title in their history. Following the capture of the league title, he helped AZ claim their very first
Johan Cruijff Shield in the
2009 edition of the tournament where AZ defeated
Heerenveen. In the
2009–10 season he was named team captain of the side in which he held that position until the end of
2010–11 Eredivisie where he left the club in the summer after six seasons to join Sporting Lisbon of Portugal. During his time with AZ, the Dutch media frequently compared him to English midfielder
Steven Gerrard due to his strong presence in midfield, his vision and his technical ability.
Sporting CP Schaars signed for the Portuguese side
Sporting CP on 16 June 2011 on a transfer worth 850,000 euros. He was one of many new players bought by Luís Godinho Lopes under the management of
Domingos Paciência who also bought other foreign players like
Alberto Rodríguez,
André Carrillo,
Elias Trindade,
Fabián Rinaudo,
Oguchi Onyewu and
Ricky van Wolfswinkel. Under the management of Domingos Paciência and later on in the season
Ricardo Sá Pinto he was a regular in Sporting's season. He scored his first goal for the club in a 3–2 away win against
Rio Ave. The following matchday, Schaars scored his first goal at Estádio José de Alvalade. He opened the scoresheet in Sporting's 3–0 home win against
Vitória de Setúbal. Following excellent displays during his first few months with Sporting, he attracted interest from several big European clubs of which included
Barcelona and
Olympique de Marseille. Despite Sporting having a disappointing domestic club finish where they finished behind
FC Porto,
Benfica and
Braga in the
2011–12 Primeira Liga, Schaars played a pivotal role in Sporting's cup competitions. He helped Sporting reach the
2011–12 UEFA Europa League semi final stage where they lost to
Athletic Bilbao, 4–3 on aggregate. Schaars was also part of the side that reached the
2012 Taça de Portugal Final where they lost to
Académica de Coimbra, 1–0. Following the 2011–12 season, he was linked with a move to
Premier League side
Fulham. Following the start of the
2012–13 Primeira Liga, he suffered an injury, for which he received surgery, which led him to miss several league, cup and European games. Schaars returned in Sporting's European away game to
Videoton FC on 4 October 2012.
PSV On 13 July 2013, it was announced that Schaars returned to the
Eredivisie by making a transfer to
PSV. PSV paid €1.6 million for both Schaars and his teammate
Santiago Arias.
Heerenveen After his contract was not renewed at PSV, Schaars joined
Heerenveen in July 2016. ==International career==