The Spireites' injury woes continued on Saturday with injured pair Liam O'Neil and Lee Novak substituted during the match with Wigan Athletic.
O'Neil was removed towards the end of the opening period after a clash of knees with Latics defender Donervon Daniels, a collision that saw the Spireites right-back limp away early from the action.
Rodger Wylde, the club's head of sports science and medicine, assessed the injury: "On Saturday Liam sustained a right knee injury that looked like a subluxed patella (dislocated kneecap), which means that the kneecap came out and tore the ligaments in that area.
"The good news is that the medial collateral ligament is intact. He's been sent for a scan today as we need to clarify the damage in the area. If it's just confined to the original tear than he should be back in about four weeks."
Another player to hobble from the action was Novak, but there's better news for the on-loan forward.
Wylde noted: "After his concussion he was fine, but had to come off on Saturday with one of the least severe injuries we have at the moment, which is a haematoma - a dead leg.
"He was in for treatment on Sunday and in again today and he's much better today. Players often disrespect a dead leg and if you treat them properly they're resolved very quickly, but if you don't they can linger so we're doing the right things with Lee and he should be back in training tomorrow."
Two players missing from the starting line-up for the Wigan match were Sylvan Ebanks-Blake and Drew Talbot, with the pair now working their way back to full fitness.
"Sylvan is building up to full training on Thursday after his hamstring injury," said Wylde. "He's a good prospect to be ready and fit for Colchester. Drew is in a similar position but we're not as optimistic about his chances for this weekend because his is an ankle injury which is more complicated."
There's also positive news for Angel, who ruptured has anterior cruciate ligament in training a week ago but is already preparing for surgery.
Wylde said: "We knew that he'd ruptured his ACL after his scan last weekend we've been getting the range of movement back, which is needed before the operation is done. It usually takes about a month to be ready.
"Angel's got full extension back already and we've been in contact with the surgeon and he's happy to proceed so he's going down to London on tomorrow with a view to carry out the operation on Wednesday, which is great news ahead of his recovery."