Armstrong supposedly had conversations with several teams regarding Halak, including the Philadelphia Flyers and New York Islanders, and is expected to continue exploring his options in the coming days and weeks.
The Blues also entertained the thought of trading netminder Brian Elliott, but nothing was consummated.
According to the St. Louis Post-Dispatch, if the pace continues, both Halak and Elliott will be back in time for training camp in September.
"I would say now that all indications are that Jaro, Brian and Jake (Allen) will be the three games at camp," Armstrong told the newspaper. "And that's an interesting one.
"When the season ended, and the emotion subsides....I talked to (head coach Ken Hitchcock) probably about this situation more than anything....where we would have been if we didn't have one of these three guys last year? So if there's something that's a way to improve our team, we always look at doing that. But it's a strength, for me, after a time of reflection."