The midfielder successfully came through his first 45 minutes since November as our reserves drew 1-1 against Palace at Selhurst Park on Tuesday night.
Simon was naturally delighted afterwards and coach Clive insisted it was just reward for all his hard work in rehabilitation.
"He's been away a long time and it's been a frustrating time for him," said Clive.
"He's been down and everyone has felt for him because he's been very unfortunate but everyone knows his attitude is first class and we all saw that on Tuesday night.
"It's a case of not running before he can walk. I've seen him every day and the work he's put in, you know that as soon as he gets the chance to play, he wants to play as long as he can.
"Simon understands the regime he's on and that is working well for him. He'll only get better and better.
"He was energetic and I thought we saw in glimpses what he's capable of. He's a quality player.
"He said he was blowing at the end of the half and it was always the plan to give him 45 minutes and I'm pleased to report that he's come through that unscathed, he can look forward to building on that."
Clive Allen described Simon Davies' attitude as 'first class' as he's battled his way back from a virus.