One day after US coach Jurgen Klinsmann pronounced Donovan fit despite the American playmaker suffering a left knee injury in a Major League Soccer contest, an MRI exam showed enough damage to shelve him from the line-up.
Donovan is the all-time US leader with 49 goals in 130 matches and his absence magnifies Klinsmann's decision not to call upon Jozy Altidore, who has eight goals in eight league matches for Dutch side AK Alkmaar.
Instead, Klinsmann selected MLS strikers Eddie Johnson and Alan Gordon to join Herculez Gomez from Santos of Mexico and Tottenham dangerman Clint Dempsey on the US frontline for the crucial matches.
Shea, nagged by an abdominal strain, will continue treatment in Dallas. Neither Shea nor Donovan will be replaced in the training camp for the Americans, who fly out on Thursday for Friday's match at Antigua.
"It's unfortunate for Landon and Brek that they won't be able to play," said Klinsmann. "Landon was very optimistic over the weekend when his knee was feeling much better, but now he needs time to recover.
"We knew Brek was a question mark coming in, and now we have a clear picture of where he stands. We feel confident that the group we have will get the job done."
It's a more formidable task than Americans are accustomed to facing in the semi-final round of CONCACAF (North American) regional FIFA World Cup qualifying.
The Americans are level with Guatemala atop their group on seven points and even in goal difference and goals scored, with Jamaica third on seven points as well but trailing in goal difference. One of the squads will not advance.