Valencia has been out of action since September after suffering a badly broken ankle in United's Champions League game with Rangers.
There were initially fears that he would be out for the remainder of the season, but the winger is close to a return to action.
The 25-year-old has been back in training for the last few weeks and he could be involved in the squad for this weekend's FA Cup quarter-final clash with Arsenal.
Ferguson is delighted to have the Ecuador international back and feels his pace and penetration has been missed down the right wing.
"He was fantastic last season, absolutely brilliant," the Scot is quoted as saying in The Sun.
"He was a great signing, he really was.
"The great thing about him was he takes the ball with such great strength and balance. He can take the ball up to the other end of the pitch for you. We missed that pace and acceleration.
"Although Nani has done fantastic - I mean he's been a revelation this season - we've missed that."
