Career
Smallwood"s natural position is the holding role in the centre of midfield. He has also been known to play centre back. He is a product of the Middlesbrough Academy and later became captain of the reserve team
At the start of the 2009-2010 season, Smallwood signed his first professional contract with the club
Smallwood made his debut for Middlesbrough on 19 October 2010 in a 1–0 away defeat to Nottingham Forest. In January 2011, Smallwood signed a 18-month contract with the club
However, in the 2013-2014 season, Smallwood soon lost his first team place following new arrivals. Under the management of Aitor Karanka, Smallwood was among the players to be offloaded as part of Karanka"s reducing the squad size.
On 23 January 2014, Smallwood joined Rotherham United on loan for the remainder of the 2013-2014 season.
Shortly after arriving at Rotherham United, Smallwood quickly went straight into the first team He was sent-off for a late challenge on Billy Knott, as Rotherham United beat Portuguese Vale 1–0 on 21 August 2014. As a result of the challenge, Smallwood had to serve a three-match suspension, missing the last two games of the season and one match in the play-offs.
After the match, Smallwood said it was the first time he had taken a penalty in his professional career.
As a result of his good performance at Rotherham United, the club made a bid to sign Smallwood in early July, only to be rejected by Middlesbrough. Initially signed in an emergency loan deal, Smallwood signed for Rotherham United on a permanent basis after Middlesbrough accepted a £175,000 bid for him.
Smallwood scored his first ever goal for Rotherham United in their 3–3 home draw with Derby County with a sublime free-kick from the edge of the area.