John O'Shea says Aiden McGeady's ability to beat defenders will make him a match-winner for Sunderland this season.
O'Shea has seen McGeady's individual quality at first hand on international duty, with the winger a key part of Ireland's qualification for the 2016 European Championships.
The 31-year-old made an encouraging competitive debut on Friday night, a constant threat to Derby County's defence and also impressing with his set-piece delivery.
O'Shea said: "The manager took him on loan to Preston last season, saw what kind of player he is at first hand, a match-winner. The confidence he got from that, the manager has brought him up here, he’ll be a great player and he will excite the fans too, I’ve seen at close hand his ability, his skill taking players on, going left, going right.
"He can deliver the cross and get assists but score goals as well. He’s getting up to speed with the games, having come in that little bit later, but he’ll be a really big player for Sunderland, that’s for sure."
The sale of Jeremain Lens means McGeady is likely to take on a key creative role for the Black Cats this season.
Wahbi Khazri could also leave the club before the transfer window shuts, the Tunisian surprisingly an unused substitute on Friday night.