Carruthers scored for the first time in 2005–06 with the winning goal in a 1–0 victory away to Grimsby Town on 10 December 2005 after scoring from a free kick on 80 minutes. He played regularly after signing permanently, appearing in 45 matches and scoring once in his first full season at the club. Ahead of 2006–07, Carruthers said "We've got a good set of players and have proved that – especially away against some of the top sides. We're capable of getting results; we just need to get that consistency". He played in an FA Cup fourth round match against Championship team Derby County on 27 January 2007, in which he cleared an Arturo Lupoli header off the line, although Rovers lost 1–0. He played in both legs of Rovers' play-off semi-final victory over Lincoln City, which finished 7–4 on aggregate. He played in the 2007 League Two play-off Final at Wembley Stadium on 26 May 2007, which Rovers won 3–1 against Shrewsbury Town, thus earning promotion to League One. He finished the season with 54 appearances and agreed a new one-year contract with the club in July 2007.