Sunderland's under-21 side beat Middlesbrough 1-0 yesterday evening.
Sunderland’s under-21 team took on Middlesbrough at the Riverside Stadium earlier this week, and they managed to pick up a 1-0 victory.
Jeremain Lens, Billy Jones and Wes Brown were all named in the starting line-up for the development squad fixture.
And Welsh said: "They all worked really hard, they were terrific all three of them.
"Billy worked very hard and defended very well, same with Wes Brown, his distribution was very good and his quality and experience speaks for itself.
"Jeremain worked hard and could have scored. He went back into midfield when we didn't have the ball.
"Their attitude was first class, they have bought into the fact that the boys are top of the league and they didn't want to let anybody down.”
Lens, Jones and Brown are all working their way back to full match sharpness, as they look to play a part before the end of the campaign.
Lens’ return, in particular, will be a big boost for Sam Allardyce, as he has the potential to enhance the quality of their attacking play.
The Dutch international has now played twice for Sunderland’s under-21 side, as he steps up his comeback from a hernia injury.
Sunderland’s under-21’s victory over Middlesbrough has moved them four points clear at the top of the Barclays Under-21 Premier League standings, but their nearest rivals, Manchester United, have played three fewer matches.