Ross Wallace has hailed the work of Roy Keane in getting Sunderland promoted to the Premiership in his first season in charge.
Keane arrived at The Stadium of Light in August with Sunderland struggling at the wrong end of the Championship table.
The Black Cats have steadily climbed the league during the Irishman's tenure, and their return to the top-flight was confirmed last weekend.
"When he came into the club we were really struggling," midfielder Wallace told the Daily Record.
"I think most fans just wanted him to keep the team in the Championship because they were at the bottom and without a win.
"Working with him has been great. He doesn't mind us having a night out but when you are there to work, you work. Nothing else matters."
Wallace linked up with Keane on transfer deadline day last August, having played with the former Manchester United skipper while at Celtic.
"I wasn't really enjoying it at the end of my time at Celtic. I was in and out the team and played out of position at left-back," he said.
"So when Roy Keane came to me and asked, 'Do you fancy coming with me down to Sunderland?', it was pretty hard to say no."
The 21-year-old has set his sights on impressing Scotland boss Alex McLeish next term and winning a call-up to the national team.
"It's a dream for me to play in the Premiership and my hope is that I can catch the eye of Alex McLeish," Wallace added.
"He said if I continue to do well then he'll have a look. I want to play for Scotland so that would be a great incentive for me.
"Sunderland have been great to me. This is a massive club who the fans utterly love. I'm really happy to be here."