The 20-year-old full-back was signed on Saturday morning and made his debut in the 2-0 defeat at Wycombe.
But he limped off after just 15 minutes after making a tackle – and club staff hope he has simply tweaked ankle ligaments, rather than done any serious damage.
Earl had a scan yesterday afternoon and is expecting to hear of the results later today.
Wanderers host Coventry City this weekend but have not yet confirmed how they will sell tickets for the game.
Several options are being examined but with a large visiting contingent of supporters expected, there are potential logistical problems to be negotiated.
The club say they will release details as quickly as possible and are thought to be looking into ways fans can download tickets or print tickets in advance of the game to save on queues.
Wanderers boss Phil Parkinson does not know if he will be able to add to his squad – now a man down after Earl’s injury – in the coming days.
But he has praised the attitude of senior players, scholars and backroom staff as they pulled together to make the Wycombe game happen.
“It has been very draining on everyone at the club, not just me and the players, the staff too,” he said. “The club doctor hasn’t been paid in a year. He drove all the way down to Wycombe on his own expense because he was concerned there would be a lot of youngsters playing in hot weather and wanted to be there to offer any medical assistance. That’s the kind of people you have behind the scenes at this club.
“Nicky Spooner and Gavin McCann drove down on the morning of the game because we needed some players, again at their own expense.
“Everyone is trying to do their bit to try and keep the credibility of the club together. They want to give the new owners a belief that there is a club there to take forward.”