Paul Sturrock is hoping to get the best out of Wright-Phillips who scored 24 goals for the Saints in 121 games.
"He was kind of an in-and-out player at Southampton - I think it's time to rekindle his career," Sturrock told the club's official website.
"It's time for him to work his passage to get himself back to the standards he has achieved in the past, and I think we're the right kind of club for him.
"When he started at Manchester City, he was very bright, but his career has taken a nosedive over the last two or three seasons.
"We've just got to turn him on, to find and push the right buttons. We'll be working very hard with him.
"The reason why I went down the road with him is that he's done it before, and I am very confident he will do it again.
"He's seen it, done it, got the t-shirt, but he hasn't done it very often lately and we have got to find out what makes this boy tick very quickly."