The Manchester United winger has heaped praise on his team-mate.
Fellaini has been a different player this season compared to the struggling star on show at Old Trafford last campaign, most recently impressing against Tottenham Hotspur on Sunday afternoon, when the 27-year-old opened the scoring for Manchester United.
And Young has spoken of Fellaini's importance to the current United side, especially as he is providing use as a virtual striker - a handy asset considering the struggles of some of the Manchester side's actual out-and-out forwards.
"He has been very important for us. He has been in the team and, when he is in the box, I'm not sure many teams can handle him," Young told Sky Sports.
"You saw against Tottenham that he was fantastic at getting in the box and looking like a striker at times. I think he likes playing in that position. We just have to utilise his strengths and I think we did that really well on Sunday.
"I think last season was difficult for a lot of people and this season is totally different."
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As Opta stats show, the Manchester United man has been performing leaps and bounds ahead of his debut campaign at Old Trafford under David Moyes.
Under Louis van Gaal's stewardship, the Belgian averages far more goals per game (scoring in the first place is a marked improvement) and wins more dribbles - and even headers, an area he consistently produced in despite his struggles.
The fact Fellaini is yet to register an assist in the Premier League this term is also somewhat of a moot point, as the 27-year-old averages more than double the amount of chances created per game he did last season.