And he now believes he can take his game to the next level thanks to the impact of Dean Ryan and his backroom team.
He said: "The way we've been training lately has been really helping my game. Bringing in the extra detail has been good for us.
"This has been the hardest pre-season I've done both mentally and physically. I've lost 10kg already and I'm in the best shape I've ever been in."
Matavesi and his teammates returned to Sixways this week after spending the first six weeks of pre-season at Malvern College. And the 22-year-old was quick to pay tribute to the atmosphere around the club.
He continued: "All the new players are fitting in well there's good banter going around which is what you need as a team. We're working hard but we're really enjoying it as well.
"We've been doing a lot of fitness and a lot of running. We ran up the Malvern Hills, which took a long time but we got each other through it."
With the new season just around the corner, Matavesi insists his side can be a match for any team if they perform to their capabilities.
"Dean has come in and it's like starting again at a new club. It's a completely clean slate and I'm really looking forward to the season now.
"We want it that way. We want the best teams to turn up at Sixways so we can show them the new Worcester.
"We're not looking too far ahead and we'll take every game as it comes. We'll go to Welford Road on the opening weekend of the season believing we can win."