Midfielder Cole Skuse is facing “three or four months” on the sidelines as he recovers from the knee surgery he underwent earlier in the week.
The 34-year-old picked up the injury in training just prior to the Cambridge United friendly and had what was expected to be a minor operation on Monday.
However, once the issue was looked at the injury was more significant and the veteran is now facing a longer than anticipated spell out.
"About three or four months,” manager Paul Lambert said when asked how long he expected Skuse to be out of action.
"So he’ll be out for that length of time and that’s a blow because that was just a slip on the grass.
"When you go from different surfaces on the training ground that can happen. We lost Cole due to a purely accidental slip on the grass, and that’s an absolute blow that one.”
Regarding, Downes's injury, which he said on Tuesday would keep him out for two or three months, he added: "It's his medial ligament that has been hurt a little bit.
"Hopefully, he's a quick healer, and hopefully, he can come back as quick as he can.
"He's doing alright, I spoke to him the other day on the phone, so he's keeping his leg up in a brace I guess, but he's doing alright, he's doing okay."
Does he feel he has enough cover in midfield with Skuse out and Downes sidelined for three months with a knee injury?
"We don’t know” he admitted. "Emyr [Huws] is still pushing everybody to get in. I know Judgey [Alan Judge] can play there as well, so we’ve still got a few numbers in there.
"Gibbo [Liam Gibbs] did really well the other night, Brett [McGavin] did really well the other night, I don’t want to put pressure on those kids at all, but we have to wait and see. Hopefully we’ll have no more injuries that’s for sure.”
Lambert had planned to send McGavin out on loan to gain first-team experience but says he may now look to hold on to the 20-year-old as cover.
"I don’t know," he said when asked whether that was the case. "With the number of games we’ve got, as I’ve said before we’re down to the three [that have been starting, Andre Dozzell, Jon Nolan and Teddy Bishop], Emyr's four, Judgey can do the role, Brett did really well with Gibbo, he did really well too, but they’re kids, they’re young kids.
"For them to sustain it game after game after game is hard, but the two of them the other night showed me that they can play the game.
"Not that I needed convincing because I knew they could do it [in individual matches], it’s the consistency game after game after game. We’ll have to look at that.”