In January 2010 it was announced that Porter was among nine players who had signed contracts with Ulster, meaning he would play for the senior side starting in the 2010–11 season. He made his full debut for the senior side on 11 September 2010 in the 2010–11 Celtic League, coming off the bench against Italian side Aironi. He also featured off the bench against Edinburgh and Cardiff Blues. However, having started off the season as second choice to Paul Marshall at scrum-half, the signing of Ruan Pienaar saw him drop to third choice and Porter finished the season with just three league appearances, all as a replacement.