At the end of the January transfer window, Sunderland announced the signing of former player Jermain Defoe.

However, the striker stayed at the club for under two months before announcing his retirement from football mid-season.

The signing was a somewhat controversial one even at the time when manager Lee Johnson expressed his concerns over the 39-year-old's lack of fitness and was more interested in pursuing younger alternatives, although he was overruled by those above him.

Furthermore, following Johnson's dismissal and the appointment of Alex Neil, it became clear that under the Scotsman he would not be a first choice player making just two starts and five substitute appearances before announcing his retirement.

Having not scored any goals on his return to the Stadium of Light, it was a move that seems to have been a poor one for all parties although sporting director Kristjaan Speakman has defended the move to re-sign the player as he told The Northern Echo: "I don't necessarily look back on it and say we should or shouldn't have done it. I just think that we make the best possible decision we can as a club that, given time, sometimes they work or don't work.

"Did this one have more risk? Of course, it did. Because of age profile, playing history, etc. But at the same time, there will be other risks that we have taken which were really successful that we don't talk about because they have been successful. Therefore, it is what it is."

Defoe's departure did leave the Black Cats short of attacking options towards the end of the season when Nathan Broadhead was injured or Ross Stewart needed a rest but Speakman feels that despite it being a blow, Defoe's decision was the right one as he said: "Jermain came to that conversation [when he signed] full of optimism on what he felt he could come and provide.

"The environment in the changing room is one of the components that has got us over the line, and what you don't want in that type of scenario is people who are not committed.

"If you look round, I was really confident of the play-offs because I could see a group of individuals that had the bit between their teeth and they wanted to be the group that got Sunderland back into the Championship.

"I don't think within that, you can have people that are big-parts. I think Jermain made a really tough decision that he felt that he couldn't continue. It's not ideal because naturally you lose a player out of your squad, and whether that is through injury or something else that can create an issue."

The Verdict:

This move definitely did not work out the way either party would have hoped for it to and to call it a failure feels justified.

However, with Sunderland having now achieved promotion back to the Championship it will be a lot easier for Speakman to talk about it in a more positive way as he knows this decision didn't cause his side any damage in their final games of the season.

However, if the Black Cats had stayed down then it could have easily been linked to this as ultimately Sunderland spent their money on paying the wages of a player who couldn't produce the standard of performance they wanted anymore and would then go on to retire midway through the season.

Therefore, although it didn't cause them too much harm this season, going into the Championship the Black Cats will have to ensure their business is done with more of a long-term focus.