Predecessor Steve Bruce spent much time and effort trying to lure former Newcastle left-winger Charles N'Zogbia to Wearside from Wigan, but lost the race for the £9.5million Frenchman's signature to Aston Villa. However, with injuries limiting his options in recent weeks, O'Neill has turned to 22-year-old James McClean, and has been richly rewarded.
The Ulsterman said: "I couldn't be more pleased with him. He has come in and he has been exceptional. He came on in the game when perhaps maybe we seemed to be chasing lost causes against Blackburn and lit the place up. His emergence has been fantastic."
McClean, a £350,000 summer signing from Derry City, made his debut as a substitute in the Blackburn game - O'Neill's first in charge - on December 11, and the pace and direct approach he brought to the side has been cited by many as the inspiration for a late fightback which transformed a 1-0 deficit into a 2-1 victory.
He has since forced his way into O'Neill's starting line-up for the Barclays Premier League victories over leaders Manchester City and Wigan since the turn of the year, and is likely to retain his place for Sunday's FA Cup third round trip to npower Championship Peterborough.
His willingness to run at defenders has already established him as a crowd favourite, although his manager has also been impressed by his work-rate and sense of responsibility.
O'Neill said: "He can go for it, but he also works back and he will do defensive jobs for you. He is just learning the game.
"He has just played two consecutive Premier League games in 48 hours, and I am quite sure that wasn't something he would have been thinking about maybe four or five weeks ago."
Source: PA
Source: PA