Newcastle had a fitness plan in place for Alexander Isak had he remained at the club this summer, and by their estimation they did not expect him to be back to his best for two months.The prolonged transfer saga between Isak and Newcastle came to an end on deadline day, with Liverpool and the player getting the move they had waited all summer for.Isak, however, signed after a disjointed pre-season that left him training in isolation and without any pre-season matches, leaving him with plenty of time to make up.Liverpool will have a plan in place for his integration into Arne Slot‘s side, but he wasted no time in training for the first time on Wednesday after playing 18 minutes for Sweden.According to the Chronicle Live‘s chief Newcastle reporter, Lee Ryder, the Magpies held the expectation that it would take Isak until “after the next international break in October to get back to his best levels.”View this post on InstagramA post shared by This Is Anfield • Liverpool FC (@thisisanfield)The club’s staff were left with “major concerns” over his fitness levels despite working individually with Newcastle‘s sports science department.If that were the case, Isak would not be at his best until Liverpool host Man United on October 19, the first game back from the break and seven weeks after he officially became a Red.Not a bad time to hit his stride, but there is plenty of time between now and then to build up the striker’s match fitness levels. Liverpool will not rush Isak’s integration into the team, as they will prefer to bide their time rather than rushing the Swede and potentially seeing him succumb to an injury.The expectation will be that he is introduced off the bench before building up to a starting berth, which could, optimistically, come against Southampton in the Carabao Cup on September 23.