Houli turned in a series of strong performances in the 2008 pre-season NAB Cup tournament, including with 17 disposals in the first half of a match against that saw AFL Media label him among his side's best players. In addition to previous roles as a half-forward and midfielder, he began playing as a half-back during this time. Those efforts saw him hold his place into the season-proper, where he played in a dual role as midfielder and half-back and recorded 26 disposals in a win over the that earned him the league's first Rising Star nomination of the year. Though he missed round 9 with a virus, Houli otherwise held his place at senior level over the first 11 weeks of the season, playing primarily on the club's half-back line, including with a two-goal, 23-disposal game in round 5 that earned him his first Brownlow Medal vote. To that point he ranked third in the club's best and fairest count. Houli missed round 12's match against West Coast with a groin injury, which after several weeks of rehabilitation and little progress, was identified as the beginning of osteitis pubis. The injury required surgery to repair and would effectively rule him out for the remainder of the season. Houli played 10 AFL matches and averaged 19 disposals per game in 2008, earning himself 17th place in the club's best and fairest count.
