The youngster made more appearances than any other first team member last season (53) and is the only player to feature in every game this term.
But Rooney, speaking on talkSPORT, noted that Rashford would benefit from picking and choosing when he tracks back.
“Sometimes, early on in my career I was working too hard tracking back and Alex Ferguson sat me down,” he said.
“It does affect when you’re in the opponents’ box. You’re a bit leggy. Alex Ferguson told me not to do so much work and be ready for when we get chances.
“I feel with Rashford it’s maybe a bit of the same. You see him going back into the full-back areas.
“It’s great he’s got that enthusiasm but, to get the best out of him going forward, he maybe needs to let the defenders and the midfielders do it.”
Even Rooney at the ripe age of 32 still struggles with the very maxim being espoused here, such is the Englishman’s natural inclination towards ubiquitousness on the pitch, and Rashford certainly belongs to the same grapevine in this respect.
But the case of Rooney ought to teach Rashford a valuable lesson. The mileage the former United captain has clocked up probably outweighs than what was necessary, and the effects during the latter stages of his time at Old Trafford were obvious.
The 20-year-old, therefore, should not abandon his effervescent style in any sense but rather think carefully about when he employs it.
Jose Mourinho often refers to ’emotional balance’ on the pitch and this issue falls under that category.