Championship news: Sunderland boss reveals Everton striker reaction, Middlesbrough forward in-demand

The Black Cats will now look at securing a replacement and the head coach has hinted that progress has been made in establishing some potential targets who could be available.

"It's frustrating for us all, I spoke to Ellis in the hotel before he left and I think he was a bit frustrated as well but he's their player," Mowbray said.

"It's good that he is catching the eye of his manager and Everton's supporters to think that he can come and help them in their battle. Everton is an amazing football club and Ellis is a young guy on a journey. He was great for us and really took the mantle on when Ross wasn't available. We're disappointed but delighted for him."

Middlesbrough striker in demand

Middlesbrough’s in-form striker Chuba Akpom is in demand, with Premier League trio Crystal Palace, Everton and Southampton all said to be tracking him.

Akpom took his goal tally to 12 for the season and nine in his last 10 matches with his treble in the 4-1 victory over Wigan Athletic on Boxing Day, which moved Boro to within two points of the top six.

The Daily Mail report: “Crystal Palace, Everton and Southampton are monitoring the Championship’s top scorer Chuba Akpom as they seek additional firepower in January.

“Former Arsenal youngster Akpom, 27, has fired himself into contention for a top-flight return thanks to his impressive form this season.”

Ross Stewart update from Sunderland boss

Middlesbrough are keen on Sunderland striker Ross Stewart – but they may have to be patient.

It comes as Tony Mowbray brushed off the latest speculation about Stewart's future as he insisted the striker is enjoying life back in the starting XI.

Stewart has made a stunning return from the thigh injury that sidelined him for much of the first half of the season, scoring his fourth goal in four games since returning in the 1-1 draw with Blackpool on New Year's Day.

Mowbray says he is confident contract talks will continue and insisted that neither player nor club are looking for a sale this month.

"Ross has got 18 months left on his deal and there's nothing to be said really," he said.

"I think he knows he's at a football club with a huge fanbase, with huge potential and some really talented players creating chances for him to score goals.

"I don't think Ross is in any rush to do anything and I'm pretty sure the club aren't in a rush to do anything other than to try and entice him to sign a new contract. Those conversations will I'm sure be ongoing."

The need to retain Stewart this window was underlined when Everton recalled Ellis Simms, leaving the 26-year-old as the club's only recognised striker.