Jagr has 1,914 points (765 goals, 1,149 assists) in the NHL but became a free agent when the Florida Panthers opted not to re-sign him. He had 46 points (16 goals, 30 assists) in 82 games last season after finishing with 66 points (27 goals, 39 assists) in 2015-16.
Adding Jagr became a topic of discussion for the Blues after the injuries started to pile up.
"All I can tell you is that he played real well against us last year," Blues coach Mike Yeo said. "That's something that I would have to watch a little bit more tape on. But I mean, consistently he's put up points.
"It's up to us as a staff to make sure that we share our opinions with Doug and then obviously Doug will talk to everybody else on his staff. But for me personally, Jaromir is a great player. I'm concentrating on our group right now. I will offer my input in any way that I can to Doug to help give him the best chance to do his job, but my job is to make sure that we concentrate on our group."
One player who knows Jagr on a firsthand basis is Blues center Brayden Schenn. They were teammates with the Philadelphia Flyers in 2011-12 after Jagr returned to the NHL following three seasons with Omsk Avangard of the Kontinental Hockey League.
"Everyone knows what Jagr can do," Schenn said. "Whether they sign him or not, obviously he's a valuable piece to any team, a great leader in the locker room, true pro, does everything possible to get himself ready to play and obviously second in points in history of the NHL. Not much more I need to say there obviously. If that happens or not, we'll see.
"Slowing down or not, he's always kind of played that puck-possession game and he's big and strong and tough to move off the puck. Forty-five years old and he threw out 46 points last year; not many guys can do that and it's impressive what he's doing. This is news to me whether we sign him or not."