"He has shown absolutely the right attitude and risen to the occasion when called upon," Ferguson told United Review. "This boy is a very good player.
"He is incredible in training with tremendous energy and it might just be worth pointing out that a couple of his recent first-team appearances have seen us beat Arsenal 4-0 and Fulham 3-0 with other wins when he has played like 1-0 at Derby and 2-0 against Portsmouth. He never lets us down!"
Reds legend Paddy Crerand was equally fulsome in his praise of the 27-year-old.
"The team Sir Alex put out against Roma shows that the manager is utilising his squad," Crerand told MUTV. "It demonstrates the strength of the squad that United won 1-0 and made it through to the semi-finals of the Champions League.
"Park is the perfect example. He has done exceptionally well since he came back from injury, and he was excellent again against Roma.
"He is a player that has been out for a long period with injury. And when players are out for a long time, you sometimes forget how good they are until you see them playing again.
"Park has got great energy and his movement really troubles teams. He's a valuable asset to the team."