Rooney missed the start of the Three Lions' bid to book a place in Brazil with a badly cut thigh, which saw his miss a month for club and country.
He told BBC Sport that he is relieved to back with the England squad.
He said: "Obviously I missed the first two games, I am delighted to back in the squad and back amongst the lads.
"I'm just ready to go now and hopefully we can get in two good performances.
"I feel good, I've been working hard and I'm happy to have a few games under my belt at high level so I feel ready to be back playing for England."
Rooney has yet to score for United in four appearances this season, but was deployed in a deeper role to great effect to assist both Robin van Persie's goals in last week's Champions League victory over Cluj.