Eddie Howe revealed Nathan Ake is likely to return to Chelsea after watching his Bournemouth side crash out of the FA Cup to League One club Millwall on Saturday.
Chelsea manager Antonio Conte has hinted he could look to bring Ake back to Stamford Bridge, describing him as an "interesting opportunity in this window for us".
And Howe accepted he might imminently lose the versatile 21-year-old, who joined Bournemouth on a season-long loan back in June.
"It looks like that will be the case," Howe said. "It's not 100 per cent finalised yet.
"It's easier said than done to say we are going to recruit a player in similar stature to Nathan and I'm not sure there's too many out there.
"So that's going to be a difficult one for us, but we will assess our options and try and make the right decisions."
Howe, meanwhile, felt the noisy atmosphere at the Den contributed to the 3-0 defeat.
The Cherries boss made 11 changes to his team and Millwall took full advantage, with goals from Steve Morison, Shaun Cummings and Shane Ferguson securing a memorable third-round victory for Neil Harris' men.
The Bournemouth manager praised Millwall's work rate and physicality after watching his team outplayed by a club from two divisions lower in the league pyramid.
"I thought they worked extremely hard," Howe said. "It was a big physical test for us - we know what they are like from goal-kicks and corners.
"I think Neil has done a great job and the crowd played their part. They'll be very pleased with their afternoon."
Howe believes the home fans had a huge role to play in Millwall's victory, with a young Bournemouth team struggling to settle into the match.
"Whenever you come here you expect that atmosphere and expect the fans to get behind their team," Howe said. "From our perspective we have got to better at dealing with that - it's only noise.
"I've got no complaints. In terms of the result, Millwall deserved it. I can't disguise how I feel. I don't think the players threw the towel in or didn't do their best. It was a very difficult game to watch. We didn't gel."