Nathan Ake has been ruled out for six weeks with a hamstring injury - meaning he may have played his last game for the south coast club.
The centre-back, who was forced off during the 3-0 defeat to Liverpool last weekend, is a January transfer target for Chelsea and Manchester City and is not expected to be fit until the last weekend of next month.
Manager Eddie Howe told Sky Sports News earlier this week that Ake's future is "out of my hands", nodding towards a £40m buy-back clause in Ake's contract that exists for former club Chelsea.
Ahead of Bournemouth's trip to Stamford Bridge on Saturday, Howe said: "I think we're looking at about six weeks" for his recovery.
"That's conservative," he added. "Nathan could come back sooner than that, but I think six weeks is probably a fair timeline.
"It was relatively good news on Nathan's scan. The trouble with hamstring injuries, it's very difficult to give definitive timelines, it will depend on how he feels.
"He presented like it was going to be a really bad one. The scan showed it was a grade two - without going too technical - but then we've had further opinions and we think we can get him back pretty quickly.
"But with these injuries you do have to be careful, you never quite know with a hamstring whether if it's fully healed or not, so we're looking at six weeks."
Bournemouth are on a desperate run of five straight Premier League defeats and sit just one point above the relegation places as a result - and Howe admitted Ake's injury along with further problems to Steve Cook and Adam Smith is a "big blow".
"We're stretched defensively, there's no denying that," said Howe. "When you look at Steve Cooke and Nathan Ake, they've done so well for us in the middle of the pitch. To lose those two players is a big blow.
"Adam as well, who's been really consistent for us. Add Lloyd Kelly to that injury list and it's quite a chunk of our defenders not available.
"But we still believe in the players that we have, we've got a mixture of youth and experience in there. They have to step up now and show their qualities.
"Individually each of them will believe they're good enough to play regularly in the Premier League - [there's] no denying their confidence levels in themselves.
"Collectively, it will be a new back four so that's something we have worked hard on to make sure that the structures are right and the relationships are there - that's going to be the big thing."
How to follow the January transfer window
Sky Sports will bring you the very latest news from the January transfer market with the return of three shows.
Start your day with Good Morning Transfers at 9am as our team of reporters bring you the latest news and insight. Transfer Talk then follows at midday delivering analysis of the biggest stories. Then join us at 7pm for the definitive round-up of the day's news with The Transfer Show.
Meanwhile, the Transfer Talk podcast will also be back at the turn of the year with more expert analysis from here and across the continent.
And as well as tuning into Sky Sports News, don't miss a thing with our dedicated Transfer Centre blog.
Follow all the latest developments here.