[1] He played in the League Cup fourth round against First Division side Sheffield United on 3 December, The Black Cats lost the game 2–0 at Bramall Lane.
Bohs romped to the 2008 Premier Division title by 19 points from their nearest challengers St Patrick's Athletic with "Rossi" scoring vital goals against Shamrock Rovers and Cork City along the way.
[10] Rossiter enjoyed a mixed season during 2009 and was at fault for a crucial Red Bull Salzburg goal, which cost Bohemians a place in the 3rd qualifying round of the Champions League.
[11] However brighter times were ahead as Mark collected his second League winners medal in a row in November as they won the title by 4 points from rivals Shamrock Rovers.
Bohemians also had a disappointing 2010 season where the club lost their league title on goal difference and failed to make an impact in Europe where they made an embarrassing exit to Welsh side The New Saints.