His comments come after BBC Scotland revealed plans to quit the 111-year-old home of Scottish football had been included in a consultancy document commissioned by the SFA.
If given the go ahead, the proposals would signal the end of international matches and cup finals at a ground which was the biggest in the world when it first opened in 1903.
Regan asked the James Watson Consultancy firm to look into what options were available to football bosses when their lease on the national stadium expired in 2020.
But the SFA chief, currently attending the FIFA Congress in Brazil, was adamant the governing body had not even discussed the paper's findings yet.
Regan said: "It is widely known that the Scottish FA's lease on Hampden Park expires in 2020, indeed this matter was discussed publicly when we launched our UEFA Euro 2020 host bid earlier this year.
"It is our duty as a governing body to proactively explore all of the options available, in consultation with key stakeholders from across the game, so that, in due course, we can make the correct decision for Scottish football.
"To that end, a consultancy firm has been engaged to thoroughly investigate the pros and cons of a number of options, and a briefing note was circulated to the Scottish FA and Hampden Park Limited boards ahead of UEFA's Euro 2020 bid decision.
"I must stress that this process is at a very early stage - no proposals have been put forward or considered, and it is hugely misleading to suggest that the Scottish FA is focusing on whether to move away from Hampden Park.
"Given its historical importance worldwide and its place in Scottish football, Hampden Park remains a key pillar of the national game."
Hampden is owned by League Two outfit Queen's Park - but the SFA holds a lease on the 52,000-seater arena which will expire in six year's time.
The SFA are now examining whether to commit themselves to another rental agreement with the Spiders, or to even acquire the free-holding of the ground.
A source close to the governing body said that "every option is being considered" - including full or partial redevelopment of the existing stadium.
The stadium was last refurbished in 1999 at a cost of £59million - with the cash funded by the National Lottery.
Scottish Sports Minister Shona Robison said she was keen to examine the findings of the consultancy report, saying: "Hampden Park is the spiritual home of Scottish Football and is renowned across the world for providing one of the finest atmospheres in the modern game.
"The SFA have made clear that they recognise Hampden remains a key pillar of the national game and I look forward with interest to reading the report's findings when they are available."
The SFA have already put Hampden at the centre of their Euro 2020 bid.
But a source insists Scottish hopes of landing three group games and a round-of-16 tie for the 24-team Euro 2020 tournament - which will be staged across Europe - are not under threat.
"It is important to stress that UEFA still sees us as a safe bet for Euro 2020," they said.
The BBC claims Celtic Park, Pittodrie Stadium, Ibrox Stadium, Easter Road and Murrayfield Stadium are all under consideration as venues for Scotland's home matches and Scottish Cup games.
Hampden also houses offices for both the SFA and the Scottish Professional Football League, as well as the Scottish Football Museum.
The stadium was not used for either of this season's two domestic cup finals after it was handed over to the organisers of Glasgow 2014, who have converted it into an athletics arena ahead of this year's Commonwealth Games.