Manchester United v Inter Milan
Kick-off: Wed Mar 11, 7.45pm; Old Trafford, Manchester
TV: Sky Sports 2, Sky Sports HD2
Radio: BBC Radio Five Live
Ferdinand had been a doubt for United's match with the Italian Champions after picking up an ankle injury during the club's FA Cup quarter-final victory over Fulham at the weekend.
Nemanja Vidic banned for first leg of Manchester United's clash with Inter Milan
However, the England defender returned to training this morning and Ferguson does not expect a reaction, with O'Shea also in line for a starting berth after shrugging off a heel problem.
'They are both fit and they will both play,' said Ferguson.
'They both trained for the first time this morning and that was important for us.'
Ferdinand should partner Nemanja Vidic in central defence, with O'Shea filling the right-back slot.
Although long-term casualties Gary Neville and Wes Brown remain absent, along with Rafael da Silva, the remainder of Ferguson's squad are available for selection.
Ferguson has a full complement of attacking options, after confirming Wayne Rooney
was substituted at Fulham only as a precaution and not due to any serious fitness concerns of his own.
The Scot even had the luxury of resting Cristiano Ronaldo and Dimitar Berbatov at Craven Cottage, both of whom are expected to return for the encounter with Jose Mourinho's side despite Carlos Tevez's impressive performance in London.
The holders are favourites to go through after dominating Inter, especially in the first half, in San Siro a fortnight ago, although Ferguson must end a disappointing sequence of results against Mourinho, having won only once in 13 encounters with the former Chelsea and Porto manager.