Connolly joined Sunderland in the summer from Hull City and has been playing with the U21s so far. A brace in the 3-2 win over Huddersfield Town in the Premier League Cup on Tuesday night and a single strike for Sunderland U21s in the 6-0 rout of Derby have impressed the club's coaches, including first-team manager Régis Le Bris.
The Galwegian was also included in Sunderland's squad for the 2-2 draw with Leeds.
It appears a first-team debut for Connolly is just around the corner. Coincidentally, Sunderland play Connolly's former club Hull City this coming Sunday.
Sunderland U21 manager Graham Murty has explained why Connolly is setting the standard in training, despite only recently joining.
"Training with the group, he's been really good to work with," said U21 boss Murty to the Sunderland Echo.
"He's vocal and communicates with the young players. He's teaching them by example, giving them good words but he also isn't shy about getting after a few players if they fall below the standard, which is good.
"And he's a very, very good finisher. You see that in training all the time, but for him to do that in games shows he's a real threat."
Last week, Connolly opened up about his alcohol problems, which have hampered his career. Murty added that the club will do everything they can to support him, but admitted it ultimately comes down to what Connolly wants.
"We want to make sure we showcase him as well as we can and support him as much as possible, but ultimately it's down to the player to show the right attitude and take the opportunity to get sharp and fit.
"You saw [at Huddersfield], he was quite disappointed when he came off after 72 minutes, even though he was supposed to come off at 60, which is brilliant for us and a great example for the players."
Sunderland play Hull City tomorrow at 3pm in an away fixture.
