The Red Devils' assistant manager is looking for Ole Gunnar's Solskjaer's side to deliver greater consistency during the upcoming campaign
Assistant manager Phelan claims to have seen plenty of signs of encouragement, with everyone associated with the Red Devils endeavouring to bring back the United of old.
“We're piecing everything together,” Phelan told the club’s official website.
“We've asked the players to do more and we're getting that response from them. You can see the intensity in training is high.
“We need to keep pushing and pushing. We're not just preparing them for the first game of the season [against Chelsea on August 11] but preparing them for the season.
“We all know last season was difficult - a great start but poor finish. We need to make sure now that the energy, stamina and enthusiasm is in the players right from the start.
“It's not just fitness. We want them to be mentally tough as well to experience what it really is about Manchester United - it's right to the end, from start to finish.
“We had periods in games where we looked really at it and really strong but then faded. We need to get that Man Utd back, that goes right the way through 96 minutes, which is a game of football nowadays, and we're preparing them for that.
“The players have to understand how it feels to be fatigued and then go again. We're trying to get that into them, both in their minds and in their bodies.”