Saracens have ended their pursuit of South Africa second row Eben Etzebeth.
The double winners held talks over the possibility of signing Etzebeth, who has one year left to run on his Stormers contract, on a short-term basis once the Springboks' autumn tour of Europe is over.
Alistair Hargreaves' recent retirement on concussion grounds has left them exposed at lock, but director of rugby Mark McCall has revealed Etzebeth will not be providing a temporary solution.
"I don't think that will happen. Alistair has retired and we are looking for somebody who is available and eligible and they're quite difficult to find at this time of year," McCall said.
"We've been exploring a couple of options and Etzebeth was one of them, but that looks like it won't happen.
"Signing him would have solved a problem until the end of January, but after that we'd have had to find a different solution.
"It's very hard to find someone who is good enough, who is available to get into this country and who is also out of contract.
"There are some second rows who become available at the end of January so we thought we'd get a double solution, but it doesn't look like it will happen."
The next 24 hours will decide whether Owen Farrell is able to play his first match of the season when Saracens visit Toulon on Saturday.
Farrell has been struggling with a back problem sustained in pre-season but has now returned to full training and could be pitched straight into the starting XV.
"If Owen reacts well to Wednesday's training session, he'll be available for selection," McCall said.
"Owen didn't react well after last Wednesday's session, but he's much more in contention this week than last week.
"Owen's been all good with his kicking and he's done some tackling as well, so hopefully he'll be available for selection. It's quite a big shout."
It is also hoped that full-back Alex Goode will overcome a knee issue in time for the heavyweight European pool showdown.