The England midfielder has not played for his club since April 4 thanks to a knee injury and had been hopeful of returning to face Manchester City on Sunday but is finally training again and ready to play.
"Aaron has trained with the team and is back in contention. It's good to have him back," Villas-Boas told reporters. "He's a player who has had a great impact this season."
Villas-Boas added that his side would have to stay motivated against the relegation-battling Latics, just the same as for its stunning 3-1 comeback win against City.
"It's a totally different proposition [to City] but just as important," Villas-Boas said. "Wigan's ambitions are as important as Manchester City's and ours. We expect a difficult game.
"We have to understand that only the same motivation as playing against the champions will give us the conditions to win this game.
"All of our remaining five games are vital. Our destiny is in our hands and we will try to get as many points as possible."