The Uruguayan completed his 10-match ban for biting Chelsea defender Branislav Ivanovic by sitting out Brendan Rodgers' team's 1-0 defeat to Southampton at Anfield on Saturday.
And, while Rodgers has insisted a decision on Suarez's participation in the cup is yet to be made, he claimed the 26-year-old will be ready to play should he be called upon.
"It has been a really difficult time for him not playing games," he said. "How he has prepared himself over the last number of weeks has been fantastic.
"He's really chomping at the bit to help the team. Everyone knows the depth of his quality and his attitude. Once he gets back on the field again he will show what he has shown since he's been here."
Suarez has scored four goals in five League Cup appearances for Liverpool, and will be keen to make a goalscoring return to the side at Old Trafford.
United's ability to call on their main goal threat is shrouded in doubt, however, after Robin van Persie missed Sunday's 4-1 defeat to Manchester City with a groin injury.
These teams have met on four occasions in this competition in the past – two of them in finals – with Liverpool boasting a superior record having won three of those.
Their last encounter in the League Cup came in the 2003 final, when goals from Steven Gerrard and Michael Owen helped Liverpool clinch the trophy at the Millennium Stadium.
As well as van Persie, United have injury concerns over Phil Jones (ankle) and Rafael (hamstring), and David Moyes may use the competition to field some of his squad players after the disappointing defeat on Sunday.
Rodgers may have Suarez available for selection, but he looks set to be without Glen Johnson (ankle), Philippe Coutinho (shoulder), Joe Allen (hamstring) and Aly Cissokho (ankle), while Sebastian Coates is definitely out with a long-term knee injury.
The Northern Irishman will also assess the fitness of Daniel Agger (rib) before deciding whether to play the Denmark international.
