Armstrong said each player's timeline to return is not determined.
"We'll update that one when they return to practice," Armstrong said. "That's probably not as ominous as it sounds. With the type of injuries, they're dealing with upper-body injuries and I really don't want to get specific because I want to protect the players when they return, if there's not a timeline where I think we know exactly when they're going to be back, so it could be a week, it could be two weeks, it could be longer."
The Blues (11-8-2) play at the Anaheim Ducks on Monday (10 p.m. ET; PRIME, FS-MW, NHL.TV).
Parayko, a defenseman, has missed five games.
"I think surgery is the last course of action and we're trying to stay away from that," Armstrong said of Parayko.
Schwartz, a forward, has not played since Feb. 13 against the Arizona Coyotes and has missed the past six games.
"It happened that game and it was something obviously has taken a little bit longer to ... it's a different injury than we are normally seeing and we're trying to get to the bottom of it," Armstrong said. "It could be that he just needs time, but it wasn't something he walked into a game with. He walked into a game and then sustained an injury and came out of the game, so it was all based around one play."
Bozak, a forward who has missed 14 games, is on long-term injured reserve.
"We were hoping he was going to be playing by now," Armstrong said. "It's just not working out that way. I can't guarantee he's going to skate on this trip, I can't guarantee he's not, I can't guarantee he's going to skate in two weeks."
Parayko, Schwartz and Bozak join injured forward
Vladimir Tarasenko
(shoulder), who has not played this season; forward Robert Thomas (broken thumb), who has missed nine games; forward Ivan Barbashev (fractured ankle), who has missed four games; forward Jacob de la Rose (lower body), who was injured in the first period of a 7-6 win at the San Jose Sharks on Saturday; and defenseman Carl Gunnarsson (knee), who is out for the season after he was injured against the Los Angeles Kings on Feb. 22.
"Those other guys, because their injuries are more direct and medical where you can say, 'OK, that's the injury, this is the timeline,' the other guys are a little bit different so we're just going to go indefinite on those guys," Armstrong said. "Obviously, 'Gunny' is gone for the year.
"The closest guy coming back is Tarasenko by a country mile."
Blues coach Craig Berube said Friday that there was
"a good chance" that Tarasenko would return to the lineup
on their six-game road trip. The game at Anaheim on Monday is the second of the trip.
