Neither flew into Germany from Manchester with the rest of the United squad, even though Vidic did train ahead of departure this morning.
"They are both injured," said Moyes.
"Nemanja Vidic had concussion and Robin has a problem with his groin.
"Neither of them are long-term but they are not quite ready yet."
Happily for Moyes, Phil Jones did travel after recovering from a groin injury that kept him out of Sunday's draw with Cardiff.
Nevertheless, with Michael Carrick ruled out by an Achilles injury and Marouane Fellaini suspended, Moyes does have a selection headache ahead of what he conceded is the toughest match of the group.
Bayer Leverkusen have only failed to win one match at the BayArena this season - when they drew with Bayern Munich - and much will depend on whether the United boss elects to use Jones in defence or in a midfield holding role.