Shattenkirk's situation is similar to Elliott's in that he has one year left on his contract ($4.25 million) and the Blues aren't sure if they want to or will be able to re-sign him before the end of the 2016-17 season, so if possible they will try to get a valuable return for him now.
Armstrong said he doesn't feel any pressure to trade Shattenkirk for lower than what he believes his market value should be as a right-handed defenseman who can skate, move the puck and create offense.
Shattenkirk had 44 points in 72 games this season. He had 44 points in 56 games in 2014-15.
"I had a chat with Kevin's representative; I feel it's easier just to be up front with everybody on the situation and they understand it," Armstrong said. "There has been no trades here today of that type of player. Maybe my asking price is too high or maybe I value him higher than other people, but I haven't been anywhere close to what I think is representative of the value of Kevin Shattenkirk."
Armstrong said he is keeping the lines of communication open with potential unrestricted free agent forwards David Backes and Troy Brouwer. But he knows each will be talking with other teams starting Saturday, when the NHL's interview period opens in advance of noon ET on July 1, when the free agent market officially opens and players can sign with another team.