NICKY Bailey is determined to come back from injury and "help like he did last year" but boss Ian Holloway cannot put an exact timescale on the midfielder's return.
Bailey, who has been sidelined since September with a troublesome calf, played 45 minutes for the U21s in a 7-3 win over Bristol City on Monday.
The 30-year-old is likely to play a few more development games before he can be involved in a first-team fixture.
Holloway is a huge fan of Bailey and believes he made a critical contribution to Millwall's successful battle against relegation 12 months ago.
"It was good to see him playing again," Holloway said.
"He did 45 minutes and played very, very well. He stayed to watch the second half so that he could encourage the lads.
"I find him to be a fantastic bloke. We wouldn't still be in the Championship if it wasn't for Bailey.
"Hopefully I can get him fit for at least a few games later on. We shouldn't be promising things but that would be like signing another player.
"If we can get him to 60 minutes and then to 90 for the U21s, then he should be ready to come back in. We've been very careful with him because his injury was complicated.
"He wants to come back and help like he did last year."
Holloway has challenged Aiden O'Brien to break into his starting XI after the 21-year-old bagged a hat-trick in the U21s' thrashing of the Robins.
"Aiden should be able to get into my team," said the Lions boss.
"I've refused to loan him out because I believe he should be good enough to play for us.
"If he runs away from the ball like he should, then he could play in either one of the wide positions."