Barrett played alongside Hargreaves in a brief spell at Plymouth Argyle, and was pleased to see his old team mate once again as the players returned for pre-season training on Wednesday.
The solid centre-back, who wore the captain's armband last season, wasn't surprised to see Hargreaves had moved into coaching and believes it is great opportunity for both him and the club.
"I had a couple of years down at Plymouth with Chris," he explained. "I was only 18 and he was already established there but it was nice to see him again this morning.
"I'm honestly not surprised he has gone into coaching. It's a fantastic opportunity for himself and great for the club.
"He's young, enthusiastic and passionate about the game. I'm sure he'll be a great addition to the football club."
The former Palace defender was speaking at Canford on the first-team's return to training, where the entire squad were put through their paces.
Barrett added he is delighted to be back in the thick of it, and says that everyone is behind manager Paul Groves and his backroom team ahead of the new season.
"We're very confident about the new season. Paul and Shaun (Brooks) have their own ideas about how they want us to play and now they have a whole pre-season to put their ideas into practice.
"We're all fully behind it and we're going to work our socks off for them. We have a very talented bunch of lads and hopefully we can have a good season."
The experienced defender is also looking forward to training in Spain in a different climate and a change of scenery.
"It will be good to have a change of scenery and get the squad together as it's a chance to bond," he said.
"I'm sure the weather will be a lot hotter than here so that will be tough for us but we're ready to work hard - it's definitely not going to be a holiday."