London - England's record goalscorer Wayne Rooney will make his debut for second-tier Derby against Barnsley on Thursday, the club's manager Phillip Cocu confirmed.
Rooney, 34, joined Derby as a player-coach from MLS side DC United but has been ineligible to play for his new side until January.
"If a player with the qualities, career and the experience of Rooney (is available) you have to be very happy and glad he is here," said Cocu after Monday's 2-1 home win over Charlton in the Championship.
"He's fit, he can start but he will need a few games. Expectation will be high when he starts playing but we have to give him a few games to build up his minutes and get in the team.
"So maybe not perfect from the start but it's important he will get in the team as soon as possible so we get a certain shape in our team."
Rooney's debut can't come soon enough for Derby.
Their win on Monday moved them into 17th place in English football's second-tier.
However, they are still nine points shy of the play-off spots and 21 behind the two automatic promotion places.
On Monday, teenage midfielder Jason Knight scored his first goals in professional football to give Derby the three points, ending a run of seven games without a win.
Victory came despite the Rams playing most of the match a man down after Krystian Bielik was sent off for a crude challenge on Conor Gallagher.
Knight put Derby ahead in the 10th minute at Pride Park when he forced the ball in at the back post only for Bielik to see red soon afterwards.
But 10-man Derby still doubled their lead 13 minutes from time when Knight scored his second following a cross from Max Bird.
Charlton ensured a nervous finish for the home side when the south London club pulled a goal back seven minutes from time thanks to Lyle Taylor's successful penalty, awarded after Curtis Davies brought down Gallagher in the box.