The Sunderland announcement that shows the club's progress - and the key challenges ahead

That the confirmation of Sunderland's retained list for next season was such a low-key announcement is in itself a marker of the progress the club has made.

In previous years, and particularly during the turbulent League One era, the list tended to herald the beginning of another rebuild and left significant gaps to be filled all over the squad.

This time around, though, Carl Winchester is the only senior player leaving at the end of his contract and having been on loan at Shrewsbury Town this season his departure has long been anticipated. An excellent professional and a key part of the side that finally lifted the club out of the third tier, he departs with the best wishes of all associated with the club.

Sunderland's significant change of transfer strategy since the arrival of Kyril Louis-Dreyfus and Kristjaan Speakman, focusing on young players who can grow with the club, has put them in a position where they now have a core group to build from in future windows.

There has also been a pleasing improvement on contract management as a result, meaning that most of the club's most promising assets are under contract for a significant period into the future.

With at least two players under contract for almost every position on the bench, and Jobe Bellingham expected to arrive from Birmingham City in the coming weeks, Sunderland are heading into the summer window in a position of strength. It reflects a club that is better run, considerably more stable and that has started to create real long-term value within its playing squad.

The list does also crystallise some of the key work ahead this summer, though. Joe Gelhardt's return to Leeds United means that Ross Stewart is now back to being the only senior striker on the club's books, and there are doubts as to whether a) he will be fully fit to start the season and b) whether his long-term future remains at Sunderland given he is now entering the last year of his deal.

Strengthening in that position will arguably be the defining factor as to whether Sunderland replicate and perhaps even kick on from this season's success. Other areas will likely need addressing, too. While central defence is currently a position of numerical strength, Bailey Wright may yet leave the club and Tony Mowbray has made clear that he feels Joe Anderson needs a loan before being considered ready for senior football. And while Corry Evans will have a big part to play when fit, that will likely be later in the campaign and so additional cover is perhaps required. Amad's departure leaves a big gap, too, even if there is hope that Isaac Lihadji and Jewison Bennette will be ready to kick on.

Sunderland may also look to reward some of those out of contract next summer, but who have shown their class at the level. Patrick Roberts and Luke O'Nien would be two obvious examples in that category.

Mowbray expects a stronger Championship field next season and so the task ahead for the Black Cats is challenging, but the platform is now firmly in place.