Two of the workers were taken by helicopter to a hospital burn unit in Augusta, Ga., according to course and hospital officials. Their conditions were not immediately available.
The other two workers were listed in fair and in stable condition at the Medical University of South Carolina in Charleston, hospital spokesman Tim Gehret said.
Authorities said they believe the explosion occurred as workers tried to light gas stoves in the clubhouse kitchen. St. Johns Fire Department Battalion Chief Wayne Carter said there was no structural damage to the building.
Roger Warren, the president of Kiawah Island Golf Resort, said the $22 million clubhouse at The Ocean Course still is set to open for next week's Senior PGA Championship. The course, designed by Pete Dye, also is scheduled to host the PGA Championship in 2012.
The Ocean Course is a majestic seaside venue favored by tourists but remembered by the world's best golfers as the host of the dramatic 'War by the Shore' Ryder Cup in 1991.
Competitors struggled through three days of blowing wind and wayward shots. Seve Ballesteros won a hole with a double-bogey 7. Mark Calcavecchia went 8-over par over his final four holes, leaving him crying on the sand dunes. Hale Irwin shot a 41 on his final nine -- and won his pairing.
Ballesteros and Irwin plan to play in the tournament that begins Thursday.
The Ocean Course slowly disappeared from golf's major scene, partly due to a reputation it was unfair, but since then, Dye has tinkered with the course design.