SUNDERLAND manager Martin O'Neill has acknowledged that perseverance has been the key to unlocking the potential of his side after a tricky start to the season.
The Black Cats, who play Bolton tonight in an FA Cup third-round replay at the Stadium of Light, secured a morale-boosting 3-0 win over West Ham at the weekend to move away from the bottom three.
Adam Johnson, who joined the Wearside club from Manchester City last August, scored his third goal in eight Premier League games on an afternoon that also saw Sebastian Larsson and James McClean net their first and second goals of the season.
The victory was Sunderland's fourth in seven league outings following a barren spell which had seen them win only one game in 10 in the run-up to December - a 3-1 defeat of Fulham in the middle of November.
England winger Johnson in particular had looked to be struggling to find his feet in the north east, but O'Neill hopes his faith in the 25-year-old is starting to pay off following a strong performance at the weekend.
"I've said this before that Adam has found it difficult," O'Neill said.
"With respect to us he was playing with some very fine players at Manchester City. He was having little cameo roles, coming for for 20 or 25 minutes and doing very well.
"Here it was totally different. He was coming in and the expectation was very high from everyone, but not really from myself. One man isn't going to make the complete difference.
"But he, in contrast to Steven Fletcher, he found it very difficult. Steven got off and running really quickly and Adam is coming to terms with all of those things."
Meanwhile, Sunderland have completed a loan move for Senegalese defender Kader Mangane, 29, until the end of the season from Saudi Arabian club Al-Hilal.