2–2 draw with the Los Angeles Galaxy. In the opening game of the 2008 North American SuperLiga group, Mullan had a goal and an assist as Houston beat Atlante F.C. 4–0. Mullan played in each game of the tournament and had one goal and 2 assists as he helped the Dynamo reach the final, where they lost to New England on penalties. On July 23, Mullan scored his first league goal of the season in a 2–0 win over D.C. United. He had a goal and an assist on August 16 to help the Dynamo beat Real Salt Lake 4–3. He finished the regular season with 3 goals and 5 assists from 30 appearances, helping the Dynamo to a first-place finish and a second-place finish overall, 6 points off the Supporters' Shield. Houston faced off with the New York Red Bulls in the first round of the playoffs. Despite Mullan starting both legs, the Red Bulls won 4–1 on aggregate. In the group stage for the 2008–09 CONCACAF Champions League, Mullan made 4 appearances and had 1 assist, helping Houston finish 2nd in the group. Mullan and the Dynamo opened the 2009 season on February 24 with a 1–1 draw against Atlante in the 2008–09 CONCACAF Champions League quarterfinals. Houston would lose the second leg 3–0. He picked up his first assist of the season on June 13 to help Houston to a 3–1 win over FC Dallas. In their next game, Mullan set up Brian Ching in the 89th minute to give Houston a 1–1 with Real Salt Lake. On July 21, Mullan suffered an ankle injury during a 2–1 loss to the Seattle Sounders in the U.S. Open Cup semifinal. Mullan made 3 appearances and had 1 assist during the tournament. He returned to the field on August 15, coming off the bench in a scoreless draw with Real Salt Lake. Mullan made 25 appearances and had 4 assists during the regular season, helping Houston finish second in the Western Conference and third overall, one point behind Supporters' Shield winners Columbus Crew. Mullan started every game of the Dynamo's playoff run, helping them reach the conference finals, where they lost to the Galaxy 2–0 He made 5 appearances and had 1 assist during the group stage for the 2009–10 CONCACAF Champions League as Houston finished 3rd in their group, missing out on the knockout rounds. After the season,