Diarra joined Sunderland last summer but made just four starts before succumbing to a groin surgery that required surgery and sidelined him for almost three months.
The midfielder returned to action at the start of last month, but then left to represent Senegal at the Africa Cup of Nations, where he was a key member of the side that lifted the trophy in Morocco.
This evening’s game saw him make his first Sunderland start since September, and after playing a major role in Axel Tuanzebe’s own goal that opened the scoring, he claimed his first Sunderland goal with an instinctive finish after Nordi Mukiele’s blocked cross fell into his path.
“It’s a new signing for us,” said Le Bris, whose side climbed back into the top eight thanks to their joint-biggest win of the season. “We spoke together this week about a new start.
“We supported him through his injury, then through AFCON and we were absolutely convinced that when he comes back with us, he will have the quality as a player. He’s really competitive as well. He wants to win, he wants to press, he wants to score and he gives us this energy, which is really important in this league.
READ MORE:
What happened to underline Sunderland's transformation in their win over Burnley?
Player Ratings: Sunderland's star man whose strength was key - and team-mate who had 'massive impact'
“He was one of our first signings, so he set the tone for us when we decided to go with him and he agreed, obviously. He came late in the squad, but now I hope he will continue this kind of performance.”
Diarra’s link-up play with Brian Brobbey was a key factor in Sunderland’s opener, with Brobbey holding up the ball before laying it into his team-mate’s path.
Brobbey outmuscled the Burnley defence throughout the game, with his power and strength delighting his head coach.
“Brian is getting better,” said Le Bris. “I think game after game you can see how strong he is in this part of the pitch.
“I think his team-mates now want to play with him, want to feed him. When we get pressed man for man, for example, we still have this option to go long, then we can support and we can break the press. That was really important. He could have scored, maybe once or twice, but he worked really hard.”
Sunderland’s win means they remain the only Premier League side to be unbeaten at home in the league this season, with the victory representing the ideal response to the disappointing showing that resulted in a 3-1 defeat at West Ham in their previous outing.
“It was important to react,” said Le Bris. “To show once again the way we want to play, the ability to press high, to be aggressive, to regain possession. It was important to threaten the space in behind as well and I think we did that really well.
“We created chances, we scored three goals and it might have been maybe one or two more, so I’m happy with the response.
“We spoke a lot this week about the way we defended in the mid-block [at West Ham] and I think we were probably a bit too reserved. We tried to change it during the week, to be more aggressive in every phase.
“It worked well, even if sometimes Burnley had the ball. We were not passive, we tried to find the right trigger, to press and when it was possible to jump, we did it. So, it gives us energy, power, intensity in every phase.”