David Moyes has a number of first-team stars out of contract next summer, but none as important as Carrick.
The midfielder must be tied down to a new deal at the earliest opportunity, as there will be no shortage of clubs making enquiries for his services in January.
2. Adnan Januzaj - the talented teenager has exploded onto the scene at Old Trafford, and is seeking a lucrative long-term contract to commit his future to the reigning champions.
3. Nemanja Vidic - the Manchester United skipper has regained his fitness and form, and is still a rock at the heart of defence.
4. Patrice Evra - the left-back's future has been uncertain for some time with Moyes heavily linked with a move for Leighton Baines. Might be released in the summer.
5. Rio Ferdinand - at 34, the centre-back might be approached about a player-coaching role next season.
6. Ryan Giggs - likely to retire at the end of 2013/14 and join Manchester United's coaching staff on a full-time basis.
7. Fabio - failed to make the same strides as twin brother Rafael, and will probably return to Brazil on a free transfer.