Dion Dublin has questioned Nordi Mukiele's public criticism of Sunderland's mentality following the Bournemouth defeat, while Shay Given has raised concerns about the Black Cats' squad depth

Dion Dublin believes Nordi Mukiele should have kept his criticism of Sunderland's mentality behind closed doors after the Black Cats suffered another damaging Premier League defeat at Bournemouth.

The French defender questioned whether Sunderland had become arrogant following last season's seventh-place finish, delivering a blunt assessment of their performances after Sunday's 2-0 loss at the Vitality Stadium. "If I have to be honest with you, we are not good," Mukiele told Sky Sports. "Maybe because we became arrogant, maybe. This is what I think."

His comments came after Sunderland's fourth consecutive league defeat left Régis Le Bris' side 19th with four points from seven games. But former Premier League striker Dublin felt Mukiele had crossed a line by airing concerns about the dressing room publicly. Few envisaged Sunderland facing such problems so soon.

Speaking on BBC's Match of the Day, alongside former Sunderland and Newcastle goalkeeper Shay Given and presenter Gabby Logan, Dublin said: "Yeah, really strong, and if we're having a player like Martinez coming out and saying things that should stay in the dressing room, I think that is one as well.

“I think you can't have one more for the players and one for the manager. I think you've got to keep those kind of comments in-house, speak to the players, speak to them eye-to-eye, and if you've got any problems, go and see upstairs as well if you need more players."

Attention then turned to the demands of Sunderland's European campaign and whether their squad has sufficient depth to cope with competing on several fronts. The Black Cats have won their opening two Europa League games, beating AZ Alkmaar and Torreense, but their domestic form has deteriorated sharply. They now face six matches in 18 days, with little opportunity for recovery or work on the training ground. Given suggested Sunderland's success last season had created a challenge the club might not have anticipated.

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"You could say they overachieved last year; they had such a brilliant season last season, they didn't expect to get in Europe, and then you would question maybe, is their squad strong enough to compete on all fronts, because we talk about it all the time, Thursday, Sunday, it's so difficult."

Dublin questioned whether Le Bris had the personnel to manage that schedule effectively. "Yeah, and that's then down to the manager to make sure he can use the right players," he added. "Has he got enough players, has he got enough quality? Possibly not."

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The debate comes at a difficult time for Le Bris. Defensive errors contributed to Sunday's defeat, while Kevin Danso's early red card compounded Sunderland's problems. Danso will miss next weekend's meeting with Leeds United through suspension, and Dan Ballard remains unavailable with a hamstring injury.

Before that, Sunderland travel to Poland to face Lech Poznań on Thursday. Their European results have offered encouragement, but there is growing pressure to rediscover the standards that carried them to seventh last season and stop their slide down the Premier League table.