The Northern Ireland international admits he was unhappy with the constant injury niggles he copped.
"It was a bit of a frustrating season both personally and in terms of the club being successful," he told the Manchester Evening News.
"It was so frustrating for me because I picked up a few niggly injuries. What was so annoying was that with other players being out injured as well, like Rio Ferdinand and Nemanja Vidic, there were chances to get in and get a few games under your belt.
"There were windows of opportunities that I couldn't take because I was sidelined.
"But I still think I made progress from my first season. I am still maturing but think I am getting better and learning more about myself and the game every week. I think my defending has improved all round."