Alan Knill says midfielder Michael O'Connor's chances of starting Scunthorpe's opener against Wycombe are "very slim".
The Northern Ireland international, 23, had missed the Iron's first six pre-season games with a knee injury but made a 15-minute cameo in their 5-0 drubbing by Barnsley.
Knill told the club's official website: "I'd say the chances of him starting are pretty slim.
"He was excellent when he came on against Barnsley, though. We saw the qualities that he brings, he is brilliant in possession, can find a pass and move the ball around the pitch.
"He is a really good player but to start, I'm not so sure. The sooner he is back the better because he is a quality player."
Meanwhile, striker Garry Thompson should feature in Scunthorpe's trip to Adams Park after missing much of the last campaign with a groin injury, although he is is unlikely to last the full 90 minutes.