Manchester United boss Louis van Gaal has said that Darren Fletcher's proposed move to West Ham is off.
Hull boss Steve Bruce says his side's 3-0 defeat to Newcastle may have jeopardised his chances of strengthening his squad.
Rafael Benitez says Chelsea are looking to bring in reinforcements in January, saying cryptically: "We'll see if there are any surprises."
Oriol Romeu's season-ending injury has left the European champions short of holding midfielders, with their only other recognised player in that position, John Obi Mikel, on African Nations Cup duty next month.
Chelsea have been linked with the likes of Corinthians' Paulinho, Newcastle's Cheick Tiote and Everton's Marouane Fellaini.
They have also been heavily touted with a move for a striker, most notably Atletico Madrid superstar Radamel Falcao.
Speaking ahead ahead of Thursday's Club World Cup semi-final against Monterrey, interim manager Benitez said: "The club is working and always looking for good players, so we'll see if there are any surprises."
Benitez admitted the seriousness of Romeu's injury, which he suffered in Saturday's Barclays Premier League win at Sunderland, had taken Chelsea by surprise.
"Oriol Romeu was bad news and we weren't expecting something so serious," he said. "He'll be fine for the future, he's a young player."
With so few options and Frank Lampard only just back from injury himself, Benitez could be forgiven for wrapping some of his key players in cotton wool for a match they would be expected to win almost regardless of selection.
Asked whether he would field a team of youngsters, he said: "No, I intend to win. I'll pick players to win the first game. You cannot think about the final until you've won the semi-final."
Benitez admitted his squad had found it tough adjusting to the nine-hour time difference since arriving in Yokohama on Sunday, joking that his and Chelsea's main focus was "to try to sleep more than four hours".
He confirmed he had watched videos of tomorrow's opponents but betrayed the difficulty of knowing them inside out when he referred to several of their dangermen by number instead of name.
Benitez reiterated the importance of winning the Club World Cup, a message which has got through to players used to the Champions League being the ultimate prize in club football.
Defender Gary Cahill admitted being in Japan had driven home that message.
He said: "When I came to Chelsea, I came to win trophies. This is a big opportunity to do that.
"It's a fantastic competition and one that doesn't come around very often. It's hard to get into this competition in the first place. We've travelled all this way and we now want to win it.
"We've got some Brazilians in our squad and it's absolutely huge for them. It's sunk in how big it is, and we want to do well in it now."
Chelsea arrived in Yokohama on the back of two straight victories after Benitez failed to win any of his first three games in charge.
Cahill revealed the former Liverpool boss' ideas had finally begun to bear fruit.
"Defensively, as a team, we've tightened up which has given us a platform to build from," he said.
"It was hard for him to get all his points across at first because he was playing games every couple of days, but now the lads are fully aware of what strategy he's come up with and what's expected of them.
"It's working well at the minute."