Newcastle United striker Michael Owen was forced off early in last night's defeat at Derby due to a groin injury.
England striker Owen was replaced by Obafemi Martins early in the second half of the Magpies' 1-0 Barclays Premier League defeat at Pride Park.
"I just didn't want to take any risks. I let him go out (for the second half) but didn't think he looked very comfortable so I put Oba on pretty quick.
"I just hope Michael's not too serious. We don't think it will be, you can expect a little tightness with all the games he's had and particularly the two England games and, of course, he hasn't had that many over the last couple of years so he's getting better and sharper and fitter.
"Tonight he felt the groin and had he carried on and extended himself in any way, he might have actually pulled it.
"We don't think he has, we think he's going to be okay for Sunday against West Ham."