Both players will attend their sisters' weddings in California and Texas respectively and will not be with the team ahead of Sunday's CONCACAF Gold Cup quarter-final against Jamaica.
Had coach Bob Bradley has given both Dempsey and Donovan permission to leave as the rest of the team prepares for the RFK Stadium clash with the Reggae Boyz in Washington.
"As a coach, sometimes you have to make difficult decisions," Bradley said after practice on Thursday.
"Certainly, we have always respected what family means to players. In these cases, after speaking to the two players, these are important days for them and their families.
"So you weigh that vs. just the team and you balance it out and make decisions.
"When you're into a tournament like this, the days after hard games are also regeneration days," he said. "I think much of our preparation work has been done."