with the club back in the championship for the 2007–08 season, mahon continued to feature regularly during the first half of the season, making 19 appearances.<ref name="games played by gavin mahon in 2007/2008"></ref> however, in december 2007, manager aidy boothroyd told mahon that he wanted to build a squad that was ready for the premier league, and that mahon did not feature in his future plans. mahon stated — "i said to aidy that i wanted to stay, at least until the end of the season. i wanted to get a second promotion in three years on my cv. aidy explained his reasons why, and i have no grudges with him for that". mahon left watford when the club were in first place in the championship, although they would ultimately finish in sixth position. boothroyd later stated that he regretted letting mahon leave "too early". during his five-and-a-half-year spell with watford, mahon made 215 appearances and scored seven goals.