Nick Powell suffered no ill effects despite needing treatment during the first half of the 1-0 Chevrolet China Cup win against Shanghai Shenhua.
The new signing from Crewe Alexandra was shaken by a bone-jarring challenge involving Shouting Wang but continued before being withdrawn at the interval.
"I was fine," he told MUTV afterwards. "It was just a little jolt and my leg's okay. It did scare me but it's fine.
"It was great to get my first start and I want a bit more time to show people what I can do. It's a lot different to Crewe - they're in Swindon at an army camp and I'm coming here to China so it's ridiculous. I get on with most of them [team-mates] as they're a great bunch of lads and happy to be with them."
Sir Alex Ferguson was pleased with Powell's contribution, even if he did miss a good chance to open his Reds account.
"Nick Powell did well," said the boss. "It's his first game, he's only 18. But he got a really bad tackle - a sore one - in the first half. He played on but I thought it was better to take him off. He was feeling it a bit. He's two-footed, he has good balance and awareness about him. The boy looks like he can become a real top player."