The Scots, who moved on to Florida to play Colombia tomorrow after the 2-1 defeat by the United States on Sunday, arrived to find confirmation from Glasgow that McLaren will not have recovered from knee surgery last Friday in time to play in England.
"It's a major blow," Craig Brown, the Scotland manager, said. "We've now lost key players from defence, midfield and attack - McLaren, Paul McStay and Duncan Ferguson - so our resources are stretched."
Brown conceded that Whyte gave an "indifferent" display against the Americans. However, like most of the Scottish players, the former Celtic centre- back was playing his first match in more than three weeks.
Scotland will field something resembling their tournament line-up against Colombia. Gordon Durie, outstanding in attack until his half-time withdrawal with a neck injury on Sunday, is doubtful. Andy Goram is set to return in goal, while Ally McCoist, who admitted the United States game was "a good one to miss", is in line to play up front.
The American captain, John Harkes, felt the Scots looked "like a team on vacation". Whyte retorted that he had obviously not seen them training, while Brown said: "We've taken difficult away from home warm-up fixtures. Obviously we don't want to lose them, but the big picture starts next month and we're still very confident."