The 20-year-old Italian midfielder came on for the final 20 minutes of Wednesday's opening tour victory against AmaZulu FC for his first appearance in the senior side on the back of a trophy-laden campaign with the Reserves whom he captained last term.
Macheda, who netted the winner in the game in Durban, is delighted to have his good pal on tour and is predicting a bright future for Petrucci at Old Trafford.
"I'm really pleased for Davide," Kiko told ManUtd.com. "He's had a tough time at United with injuries but he did great for the Reserves last season. He deserves to be on tour and was unlucky not to score the other night.
"I've just told him to stay calm and not to put too much pressure on himself, but to enjoy the tour and do his best and just play his game. He is a great player and it's great to see him playing for the first team. I hope he'll do very well in the future."
Doing well for the Reds in the coming season is exactly what Macheda has in mind too.
"It's great to get opportunities on tour and show the manager what you can do. I just hope I can get the opportunities during the season now," he added.
"My aim is to do well on tour and hopefully become a regular in the squad next season. I think I'm ready and I can't wait to start the season."