mahon started in qpr's opening game of the 2009–10 season on 8 august 2009, playing the whole match as the club drew 1–1 at home to blackpool. he played regularly in the opening months of the campaign, making nine appearances in all competitions, scoring once, with qpr winning seven of the games.<ref name="games played by gavin mahon in 2009/2010"></ref> however, he suffered a knee injury in november 2009, which would ultimately rule him out for the remainder of the season. with mahon's contract expiring at the end of the season, manager neil warnock stated — "he'll probably come back and do a pre-season with us and try and show me what he can do. i've always liked gavin, we've just got to wait and see who's available". despite being released at the 2009–10 campaign, he re-joined the club in october 2010 on a one-month deal, describing the move as being "like a trial". although he did not make any further first-team appearances for qpr, the monthly deal was extended on four separate occasions.