Juan Mata has not played regularly for Chelsea since Jose Mourinho's return.
Chelsea's most pressing concern in the January transfer window is the recruitment of a striker with the ability to lead the line and fire them to Premier League and Champions League glory.
The current incumbents—Fernando Torres, Samuel Eto'o and Demba Ba—have flattered to deceive, leaving Jose Mourinho in little doubt that he needs to strengthen.
Is Jose Mourinho right to plan big changes at Chelsea?
In order to bolster his striking options, Mourinho is said to be planning a clear-out of deadwood to generate transfer funds, per Simon Jones of the Daily Mail, with Juan Mata's name the one that keeps appearing.
The two-time Chelsea Player of the Season has been most heavily linked with Paris Saint-Germain, via Jeremy Wilson of the Telegraph, and Napoli, per Martin Lipton of the Mirror, due to a lack of regular football and a reported frustration at Mourinho's tactics.
A move is likely, but only for the right price, as one of Chelsea's star performers in recent years becomes the first big name to feel the wrath of Mourinho's second coming.
Another high-profile casualty could be Brazil international David Luiz, whose season has not hit the heights he would have wanted it to during a World Cup year.
Previously said to be a target for Barcelona, Luiz is now heavily linked to Bayern Munich, as reported by Richard Beech of the Mirror, where former Barca boss Pep Guardiola is in charge.
The German side recently ruled out a bid for the 26-year-old, per the Daily Mail's John Drayton, but if he were available for transfer, it may be a different story, as Guardiola continues to try to improve on Bayern's Treble win during 2013.
It remains unclear whether Luiz has a major future at Chelsea under Mourinho or whether he will be allowed to leave. Should it be the latter, he won't be short of clubs battling for his signature.
An unlikely candidate for a January transfer is reserve goalkeeper Thibaut Courtois, who may be seen as surplus to requirements.
The 21-year-old Belgium international, who has been on loan at Atletico Madrid for the past three seasons, has previously been viewed as the long-term replacement for Petr Cech.
However, he is said to be growing impatient at his lack of progress, according to ESPN, with Atletico and Barcelona both named by Alex Kay of the Daily Mail as potential suitors should he become available for permanent transfer.
Spanish football expert Dermot Corrigan says that Courtois is hoping for a quick decision on his future, but Atletico may not be able to afford him:
Courtois hoping for quick decision on his future, Atletico unlikely to be able to afford him, ball in Chelsea's court http://t.co/RouJjP2htW— Dermot Corrigan (@dermotmcorrigan) January 9, 2014
At 31 years old, Cech is far from finished at the top level, and Mourinho is believed to have faith in his ability. But letting a goalkeeper of Courtois' undoubted class leave the club would be a major boost for Chelsea's rivals and attract the interest of some big names.