Fletcher, who’s now been playing for United longer than anybody else in the squad, possesses plenty of experience to judge his peers. And he reckons Herrera, who made his first United appearance alongside the Scot in Tour 2014's opening game against LA Galaxy, has what it takes to make a big impact at Old Trafford.
“He’s a really talented footballer,” Fletcher told ManUtd.com.
“He has great enthusiasm and great energy in midfield. He always wants the ball and is always looking to make things happen.
“His enthusiasm’s infectious – it’s rubbed off on a few of us already – and he works hard for the team. He wants to learn and listen, he takes on instructions well… and off the pitch he’s a good lad."
“He’s settled in really well and not only with the other Spanish-speaking lads. I think he’s going to be a key player for Manchester United.”
Herrera, 24, arrived from Athletic Club in late June, a day before teenage defender Luke Shaw also joined the Reds. And while both men will provide manager Louis van Gaal additional options this season, Fletcher believes their signings will also reap long-term rewards.
“First and foremost, they’re both great lads. They’re also top-quality players on the pitch," he said.
“There’s no doubt in my mind they’re great acquisitions – not just for the quality they bring to the team right now but for what they’ll bring in the future.
“They’re both young and should have many years ahead of them here. I’m sure they’ll develop into real Manchester United players and help us win trophies.”