Left-back Tom Clifford looks set to miss the start of the National League season with an ankle injury.
Clifford picked up the problem during Saturday’s pre-season friendly at Ebbsfleet United.
And, although the full extent of the injury has yet to be revealed, Blues boss Phil Brown fears the defender will be spending the next few weeks on the sidelines.
"Tom has been for a scan and it looks like it’s heavily sprained,” said Brown.
"There’s no bone damage which is good news but there might be ligament damage.
"We’re waiting for the scan but I’ve watched it back and it was innocuous movement when he went over on it.
"He’s definitely very, very unlucky.
"He had 20 minutes at the weekend and was looking like he would play a part in one of the games this week and the game on Saturday with a view to starting against King’s Lynn.
"But it’s looking like he will be out for a few weeks because he’s still in a lot of pain.
"Hopefully the scan will show it’s just a heavy sprain but he will certainly be out for the start of the season.”
With Clifford now injured and focus will turn to Nathan Ralph who himself is still working his way back to full fitness after suffering a cruciate ligament injury last October.
However, Brown has been impressed by Charlie Sayers during pre-season and would not be afraid to hand the youngster his competitive first team debut once the campaign gets under way later this month.
"I couldn’t believe it when someone told me Charlie was 17,” said Brown.
"He’s showing great signs and he’s playing football without any real pressure at the moment.
"We’re just helping him along the way to be a pro footballer at the moment.
"Nathan Ralph is back playing and what a great professional footballer he is by the way.
"Nathan is a great example and someone you can learn from.
"That project was going to involve Tom but now he’s injured Charlie is even closer to the first team and he was very close to it before anyway."
Sayers’ next chance to impress could come tonight as Norwich City’s U23 side visit Roots Hall for a pre-season friendly.
And Brown is looking to call upon more of his senior players against the Canaries.
"The ones who need 90 minutes will play but others will get minutes for the under 23s at Stevenage on Wednesday,” said Brown.
"There’s the capabilities to play some as over-age players against Stevenage but I have to say the fitness levels look good.
"Players are getting their minutes in and we’re looking forward to the Norwich game now."