Blues striker Ali Al-Hamadi has expressed his frustration at suffering a calf injury so early in the season.
The 23-year-old picked up the injury in the first training session after the Bromley match in which he played his first 90 minutes of the season.
"Best I’ve felt mentally and physically going into a season, so it’s really frustrating to have picked up an injury so early on in the season,” he wrote on Instagram.
"Football always has a way of testing you. Be back in a little while. Get behind the boys and see you all soon.”
Manager Kieran McKenna said he expected the injury to keep the Iraq international out of action for a number of weeks.
"Not very short term, hopefully not long term either,” he said. "He picked up an injury in the first session back after doing the 90 minutes against Bromley in the cup and it’s probably going to be a few weeks.”
Al-Hamadi might have been expected to move out on loan before the transfer window closes next Monday, assuming the Blues add to their attacking ranks, but the injury would appear to make that less likely.
The former AFC Wimbledon man, who spent the second half of last season on loan at Stoke City, had been interesting Toulouse and Luton, while Charlton and Cardiff had also been linked.
Elsewhere, former Blues loanee Lewis Travis has joined Saturday’s opponents Derby County from Blackburn Rovers on a four-year deal, reuniting with his former Ewood Park boss John Eustace.