Town boss Paul Lambert says Tristan Nydam suffered a suspected dislocated ankle in the second-half incident which saw the 19-year-old stretchered off during the 1-1 friendly draw at Notts County.
"It's a real unfortunate incident and we don't know the true extent of what the damage is,” Lambert said afterwards.
"It looks like he's dislocated his ankle, and we'll just have to wait and see how it's going to be.
"At this moment I think he's away [in hospital]. I don't have any blame attached to the lad from Notts County.
"He's been playing well [at left-back]. That's football, it's a contact sport, and unfortunately these things can happen.”
Nydam joins a long list of injured players even before the season's started with Jack Lankester (back), Teddy Bishop (knee) and Toto Nsiala (hamstring) all having picked up problems which will see them miss the start of the season, while the likes of Gwion Edwards (groin), Jon Nolan (calf) and Freddie Sears (ACL) are still recovering from injuries they suffered during the last campaign.
"Football's a contact sport, you can't take that out of the game," Lambert added.
"As I said, no blame attached to anybody, it's an unfortunate thing that happens. That's part and parcel of football, You get knocks, you get injuries, there's nothing you can do about that, that's the nature of the game.
"Hopefully we get a few lads back before next Saturday, hopefully that's going to happen. Obviously one or two are longer term but hopefully we get a few back."
He says there's nothing new on the earlier injuries with Jordan Roberts having missed this evening's game with a knock.
"No, just what it was the other day," Lambert continued. "Bishop, Lankester longer term, Nolan's doing well, Edwards' doing well, Toto's the same.
"There's a few there, Roberts should be okay. There's a few there, if we can get a few more in then let's see."
Lambert confirmed that Luke Chambers wasn't suffering with any injury issue with the skipper and Myles Kenlock having been left back in Suffolk as they played the full 90 minutes against Colchester on Friday.
"No, none, and Myles. [He stayed behind] just because he played the 90 against Colchester."