The winning goal for Luton in a 2–1 victory over Cardiff City in October was scored by Holmes from close range, which brought an end to the opposition' eight match unbeaten run. He suffered from a twisted knee during a match against Derby County on 26 December 2005, eventually returning to action from a hamstring injury in February 2006 by playing in a reserve match against Southend United. His competitive return was in a 3–3 draw against Cardiff, where he came on as a substitute for Dean Morgan on 82 minutes. He completed 2005–06 with 25 appearances and scored two goals, when Luton finished 10th in the Championship. Following the conclusion of the season, he signed a new one-year contract in June 2006. He joined League One club Chesterfield on a one-month loan on 12 January 2007, making his debut the following day in a 1–0 away victory over Rotherham United, in which he forced goalkeeper Neil Cutler into making a good save. Chesterfield were given the lead by Holmes in a match away to Huddersfield Town with a header from a Kyle Critchell cross, which eventually finished a 1–1 draw. The loan was extended for a second month on 8 February 2007, and Holmes said he would consider signing for the club permanently when the loan expired. He eventually finished his spell at Chesterfield with 10 appearances and scored one goal. He joined Lincoln City of League Two on loan until the end of 2006–07 on 22 March 2007. His debut came in a 3–2 home defeat to Swindon Town and he completed the loan spell with five appearances.