Rangers' proposal for league reconstruction is "just too early" to be put in place for 2020-21, says Ross County chairman Roy MacGregor.
Celtic and Rangers would have B teams in the bottom tier of a 14-14-18 league set-up proposed by the Ibrox club.
MacGregor is generally supportive of the idea of B teams but feels the current 12-10-10-10 model should remain for now.
"I think it's a medium-term project," he told BBC Radio Scotland.
"Making these decisions at a time when there is stress on the industry is not clever. We're going to get a fixture list out in three weeks.
"The principles seem right, it's just too early to do it this season. I think everyone needs a bit more time."
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Amid football's shutdown, SPFL clubs have discussed various models of reconstruction but none have been put to a vote as yet. As well as integrating B teams, Rangers' proposal would offer a reprieve from relegation for Hearts, Partick Thistle and Stranraer and invite Brora Rangers and Kelty Hearts into the senior set-up.
In recent seasons, Premiership 'colt' teams have featured in the Scottish Challenge Cup.
And MacGregor told Sportsound: "It needs to be right for all 42 clubs. I've always been a fan of the colt teams if they can afford it. I would like to hear what the part-time teams thought of the principle.
"The principle of developing players and getting them to play competitive football with men is really positive."