Connolly has made 12 appearances for the Black Cats.
Aaron Connolly is set to leave Sunderland just four months after joining the Black Cats, according to reports.
The Republic of Ireland striker, 24, is on the verge of joining fellow Championship team Millwall, reports The Northern Echo.
Connolly has been a fringe player since joining Sunderland on a short-term deal last September.
The former Brighton and Hove Albion forward has made 12 appearances in all competitions and scored twice.
He has, however, only started two Championship games for the Premier League promotion-chasing team.
Sunderland head coach Regis Le Bris addressed Connolly’s future last week, hinting that the player might soon be heading for the exit door.
“We need to discuss the best pathway for him,” he said. “Sometimes, it’s not your story.”
Millwall, managed by former Sunderland coach Alex Neil, are in 14th place in the English second tier, and looking to strengthen their squad in the January window.
Connolly started his career with Brighton and scored twice on his first Premier League start in a 3-0 win over Tottenham Hotspur in October 2019.
After the goals dried up for the Seagulls, Connolly had a series of loan moves with Middlesbrough, Venezia, and Hull City respectively.
He joined Hull on a permanent deal in 2023 but was released when his contract expired at the end of last season.
Connolly then signed for Sunderland on a one-year deal last September. He scored his first goal for the club against Millwall in November.
In October, he spoke about his struggles with alcohol addiction in a revealing interview on World Mental Health Day.
The 24-year-old has made nine appearances for the Republic of Ireland since making his debut in 2019.
