The Bulgarian did not recover from an ankle injury in time to make the trip to Switzerland, where United need a draw on Wednesday in Group C to secure a place in the last 16.
He is the third United striker to be sidelined, joining Javier Hernandez and Michael Owen who face another few weeks out. Anderson has been ruled out until February with a knee problem, while fellow midfielder Tom Cleverley is also missing.
Ferguson believes he has enough talented players to cope with the absences as last season's runners-up seek to avoid an embarrassing group-stage elimination.
"We have had to contend with quite a few injuries this year. We have a strong squad, that squad will see us through," he told a news conference.
"I think we have to rely on our experience away from home. It's a very, very good record," Ferguson said.
"I don't think that kind of pressure affects us. If you look at the number of big games these players play in, these players have been involved in finals and semi-finals," the Scot said.
"Tomorrow is the same kind of situation, it's a big game. It's another one."
"There is more pressure on Manchester United, in 99 percent [of cases] they are absolute favourites. They probably have 13 international players, they are so strong it is mad," the Swiss club's coach Heiko Vogel told a news conference.
"They can handle the pressure but maybe these one or two percent can be an advantage for us."
