Solskjaer’s side are chasing Champions League qualification and silverware in the FA Cup and Europa League.
United are on a 17-match unbeaten run in all competitions after a 3-0 midweek win at Aston Villa, but Solskjaer says it is tricky to look too far ahead at present.
“There’s quite a lot of planning going on,” Solskjaer said on Saturday.
“When do we start the league? That obviously is determined by how far we go in Europe, so you can’t really decide on the programme, the training programme.
“So, there’s so many small decisions and of course transfers – that’s sometimes out of our hands as well because if the team is going well, what do we need? What don’t we need? Do you get injuries?
“That’s just the way of working in this job, that you’ve always got to plan for different scenarios.
“But, the uncertainty of dates, how much holiday can you given them, how will next season look like, it’s still a little bit up in the air.”
United sit fifth in the Premier League and welcome Southampton to Old Trafford on Monday, by which time they will know if the Court of Arbitration for Sport have upheld Manchester City’s two-season European ban.
If second placed City are kicked out of the Champions League that will mean fifth place in the Premier League would secure a place in Europe’s elite club competition.
Asked if returning to the Champions League would have dramatic effect on the club in the short term, Solskjaer said: “I don’t think it’s like dramatic decisions, the word you said there.
“I don’t think the club would either panic or suddenly go crazy with plans that we’ve already talked about for the years to come.
“You have to have a long-term plan but of course short-term maybe some decisions will be easier to make if or if not you get the Champions League.”
United can qualify for the competition by winning the Europa League if they failed to do so through the Premier League, where they are just two points behind third-placed Chelsea.
They have won four successive league matches by three goals or more and Mason Greenwood has played a key role, with the 18-year-old scoring four goals and providing another during that run.
“At that age, you’ve got so much energy, you’ve got no fear,” Solskjaer said.
“You just want to go and play football. If we have a day off, he’ll go and play football with his mates.
“I’m not worried about Mason this season. We just need to look after him his whole career.”
