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."

The World War Two cipher machine was bought at a flea market by a cryptography professor, who apparently recognised its true worth.
It was sold to an online bidder in Bucharest, Romania, on Tuesday.
Enigma machines were used to carry coded military communications during the war.
First developed in Germany in the 1920s, the codes created by the electromechanical encryption devices were eventually cracked by mathematician Alan Turing and his team at Bletchley Park.
Bucharest auction house Artmark put this particular Enigma machine on sale with a starting price of €9,000.
Cristian Gavrila, the collectible consignment manager at Artmark, told Reuters: "The collector bought it from a flea market. He's a cryptography professor and... he knew very well what he was buying."
However, the eventual sale price fell far short of the record amount for an Enigma machine at auction, after one sold at Christie's in New York for $547,500 last month.
Scottish Professional Football League chief executive Neil Doncaster believes the possible advent of summer football is an issue of some complexity.
[NEXT_CONCEPT]
A 100 euros typewriter has sold for 45,000 euros (£40,000; $51,500) at auction, after it was discovered it was actually a German Wehrmacht Enigma I.