Solskjaer has asked Manchester United players to return from their holidays early and start pre-season training on July 1.
The former United player took over from Jose Mourinho in December on a temporary basis but was awarded the job full time after an impressive start at the club, which saw the Red Devils go unbeaten for three months in the league.
However, a serious dip in form towards the end of the season saw United win just two out of twelve matches in all competitions, ultimately finishing sixth in the Premier League.
But Solskjaer is determined to work on his player’s fitness before the start of the new season.
A source told ESPN:
“The players weren’t fit enough when Ole arrived.
“They worked really hard to change that in December and January but they hit the wall in the end, and that was probably inevitable.”
United’s pre-season games commence in Australia with a clash against Perth Glory on July 13, before they travel to China and Singapore for more fixtures before the Premier League kicks off on August 10.