The Republic of Ireland international has recovered from illness while the young striker has returned from a loan spell with Sheffield Wednesday, and both are available
McClean has been suffering with illness this week while Wickham was on loan at Sheffield Wednesday until Thursday, but both can be included when the Black Cats take on the Canaries at the Stadium of Light.
"Some of the senior players were able to get a game on Monday evening and that was very, very important to get some game time and get some fitness as well," O'Neill told the club's official website.
"Between now and the end of the season we'll be calling on just about everybody.
"[James McClean] was taken into hospital early on Friday morning and he was discharged on Saturday afternoon but not before he'd gone through a rigorous set of tests.
"He's recovering and, though, he's still a little bit weak, he's pushing himself forward.
"In fairness to the lad, even though he hadn't been discharged from hospital on the Saturday until around about 11am I phoned him and he asked if he could make his way down to the game.
"It shows you at least he's still keen to be involved, very keen actually and with a bit of luck if he gets through the next couple of days, he will be."
Of Wickham, O'Neill added: "Connor went out first of all to get some games and to play competitively and he's been able to do that there at Sheffield Wednesday.
"He's started matches, he's come off the bench as well at Sheffield Wednesday, and I've been able to see him play a couple of times as well against Birmingham City and against Watford.
"He's got some game time which has been very, very good and beneficial for everyone."