"I don't think any of the injured players will be back against Porto," Sir Alex told MUTV. "But we do have the suspended players back which is good.
"Vida will play alongside Jonny Evans at the back with John O'Shea moving to right-back.
"Rooney and Scholes are also available which will give us a bit more penetration and experience, and Ji-sung Park will also be ready so I've got some good options for Tuesday.
"I'll have to assess how Ryan [Giggs] is after playing the 90 minutes against Villa. It's a big ask for someone at 35 years of age to play another game two days later at the kind of level we play."