Former Middlesbrough loan flop Aaron Connolly is on the move again, as his short spell at Sunderland ended with a move to Championship rivals Millwall.

In a move that could have implications for Boro loanee Josh Coburn, Connolly left Sunderland after just four months on Wearside, with game-time limited at the Stadium of Light. Considered third in the pecking order while Sunderland pursue other strikers this month, Connolly made just three starts and scored one goal after joining on a free in September.

Joining Millwall, they are the former Boro loanee's fourth club since leaving Boro in the summer of 2022, as he struggles to get his career back on track. A flop at Boro, the 24-year-old admitted in an interview after joining Sunderland that he had struggled with alcohol abuse.

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But thanking Sunderland after his Millwall move, Connolly said: “When I spoke to Kristjaan [Speakman - sporting director], I just thanked him for the opportunity this club gave me when many others wouldn’t. It is something I will never forget and the love I felt from the fans after my first interview until my final game is something that I will always be grateful for.

"Physically and mentally, I leave Sunderland in a good place. I’m now ready to play games regularly and I appreciate the club’s understanding in allowing me to pursue this opportunity. I wish everyone at Sunderland the best of luck for what I’m sure will be a memorable end to a great season.”

Connolly's arrival at the Den comes as Boro loanee Coburn remains sidelined with an injury. His exact return date is unknown, though he recently posted on social media to suggest he was working hard on getting back as soon as possible.

When he does return, he'll face fresh competition for a spot in the team from Connolly, though the number of strikers at Millwall remains the same because Connolly's arrival paved the way for Tom Bradshaw to join Oxford United, where he links up with former boss Gary Rowett. New Millwall boss Alex Neil, meanwhile, also has Macaulay Langstaff and Mihailo Ivanovic to pick from.

On the signing of Connolly, director of football Steve Gallen said: “We’re pleased to bring Aaron into the club. (He) has been a bit unlucky not to play a bit more at Sunderland this season, but that has given us an opportunity to get him in. When Alex and I met him, we really liked his enthusiasm for what we want to do here.

"Still only 24, Aaron has a lot of experience for his age. He is at his best when running at defenders and we hope he gets plenty of opportunities to do that with us."