According to The Scottish Sun, Carlton Cole returned to Celtic training on Tuesday - but was carted off injured after suffering a knock on his calf.
Cole, 31, has been a free agent ever since his West Ham United contract expired earlier this summer, but the striker has so far had no luck in his bid to find a new club.
Now though, the former Chelsea youngster has been offered an opportunity to get back in to football. Cole spent last week on trial at Celtic, as he looks to impress manager Ronny Deila in the hope of landing a permanent contract with the Bhoys.
Cole left Glasgow in order to return to London over the weekend, but he was back in training with Celtic on Tuesday as his trial period resumed, to the surprise of some.
However, the potential move has taken a twist, with The Scottish Sun reporting that Cole was carted off with a calf injury, putting his hopes of a deal at risk.
It's unclear how long it will take Cole to recover from his injury, but manager Deila must now assess the damage before pressing ahead with any possible permanent deal, in what will no doubt be a blow to the Norwegian manager.
Given that Cole is a free agent, the deal can be completed at any time outside of the transfer window - but Celtic will certainly want to make a decision sooner rather than later, and the news makes it difficult for Deila to assess what to do with the physical target man.