Rashford had a miserable 2021/2022 season, scoring just four goals in 25 Premier League matches.
The 24-year-old did not look his usual self leading to suggestions his off-field activities, which includes campaigns against child food poverty, were having a negative impact on his output on the field.
Manchester United eventually finished sixth in the Premier League after replacing Ole Gunnar Solskjaer with Ralph Rangnick and Rashford lost his place in Gareth Southgate's England squad.
With Ten Hag now firmly in charge of the Red Devils, Rashford is looking to take advantage of the extended break he had this summer to revive his career under the Dutchman.
“For me it is a fresh start, something I am looking forward to,” Rashford said.
“The first two and a half weeks of training has been good. We have improved a lot. The team is a lot fitter than last season and we have a lot of room for improvement. I am in a good place right now – looking forward to getting more games under my belt and getting ready for the season.”
“It has not been natural [usual] to have a long break – just under four weeks, a long break physical and mentally."
“It is an opportunity to refresh. I am ready to go again. I have used the opportunity to do what I have always done and refocus. This is my first year I have been with the team since the beginning [of pre-season]. I feel a lot better than usual, when I go away with the nationals and come back partway through pre-season. It is important to get a fresh start. I feel fresh and ready.”
Manchester United defeated Liverpool 4-0 in their first pre-season game on Tuesday.