Three-quarters of Scotland's top-flight clubs have told BBC Scotland they would consider a move to summer football.
But Doncaster says the amount of games played and international tournaments have to be taken into consideration.
"We are effectively playing for 11 months and using pretty much every date we can in that period," he explained.
"We currently start in July and finish in May. The missing month is the one the World Cup and European Championship takes place in.
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"The key question is do we want to be playing games at a time when a World Cup or European Championship is going on?
"If we want to go head-to-head with those major tournaments, that's a decision we can make but we should make it in an informed way and understand what that really means."
The chief executive also highlighted the possible economic impact of changing the Scottish season.
"I think we need to look at other league formats that result in fewer games and that might create more flexibility to take games out of the worst of the winter weather," he said.
"I think most managers would agree that we play too many games but the problem with shortening the season is the knock-on impact on income, so it's much easier said than done.
"We can't simply create a winter break if we are using 11 months at the moment. We played seven [rounds of Premiership] games in January this year, not because we wanted to but because of the constraints.
"Unless there is a debate around how many games we play and the league structure, there is very little scope to alter the current calendar."
Scottish Football Association chief executive Stewart Regan was asked about summer football at his organisation's annual general meeting on Wednesday and described it as "an interesting concept".
"We are discussing a raft of matters relating to the fixture calendar," he said.
"We [Scotland] play Ireland on Saturday night and [Scottish clubs'] first Europa League qualifier is [in early July].
"The traditional close season has gone and it's important to consider how we move towards a mid-season break rather than summer football.
"So you would have two half-seasons with a gap in the middle. It's important for players to have down time and holidays and that we're managing international and club fixtures side by side."
Scottish Professional Football League chief executive Neil Doncaster believes the possible advent of summer football is an issue of some complexity.