Sunderland have endured and enjoyed their fair share of transfer failures and success over the years as they have seen flops and bargains come through the door at the Stadium of Light.

The transfer market is a difficult sea to navigate and even the best teams in the world get it wrong from time to time, with the Black Cats being no exception.

Tony Mowbray has not been in the job long enough to have a catalogue of failed signings or missed opportunities as the Sunderland manager, as many of his predecessors did.

One former head coach who was no stranger to a disappointment in the transfer market was former Manchester United and Ireland midfielder Roy Keane.

In the summer of 2007, the ex-Black Cats manager failed to secure the signing of Wigan defender Leighton Baines and was left to rue that in the subsequent years.

It was reported that the club had agreed a £6m deal to sign the left-back before fellow Premier League side Everton swooped in to sign him for the same price, with the Liverpool-born defender deciding to move closer to home.

Speaking about his decision to reject Sunderland in 2007, Baines said: 'They had worked so hard to get to that point, that it would not have been right if I had not gone up there and sat in front of him. He was very impressive and not what I expected him to be. He was very relaxed, very cool. I felt totally at ease with him and I came away thinking that, in different circumstances, I'd really love to play for him.''

The full-back had played 158 matches for Wigan in all competitions and did enough with the Latics to convince Sunderland and the Toffees that he had the potential to be a regular in the Premier League for many more years to come.

He went on to fulfil that promise as he played a whopping 420 matches in all competitions for Everton, scoring 39 goals and providing 67 assists from left-back.

Baines ended his career with 420 Premier League games under his belt, whilst he was also capped 30 times by England after making his debut in 2010.

Current Woking gem Padraig Amond claimed that the defender had a "wand of a left foot" and his aforementioned goal contributions for the Toffees back that up, as he made an impact at the top end of the pitch despite playing in defence.

Therefore, Keane was left to rue his failed swoop to sign the defensive maestro as Baines went on to prove himself to be an international-level player who competed in the Premier League for another 13 years after Sunderland attempted to sign him.