They used the No. 16 overall pick in the 2010 draft on the 6-foot forward and despite lucrative offers to stay in Russia, Tarasenko is delivering on his promise.
The Blues and Tarasenko have agreed in principal to a contract he'll sign in July as soon as the CBA allows.
"He had some very good opportunities if he wanted to say in the KHL," Armstrong told ESPN The Magazine on Saturday. "We think he's NHL-ready and we're excited to get him in the lineup."
Armstrong told Tarasenko that he is projected to be on St. Louis' NHL roster to start the season, which certainly helped the effort to get him under contract.
"We thought if he needed seasoning, we'd just keep him in the KHL," Armstrong said. "He has a roster spot to lose but ultimately it'll come down to his ability in training camp. He has to gain the trust and the respect of his teammates and coaches. All indications in watching him play, we think he'll be able to do that."
In 54 games in the KHL this season, Tarasenko scored 23 goals.
The Blues have also parted ways with defenseman Brock Beukeboom, acquired from the Tampa Bay Lightning in the deal that sent Eric Brewer to the Lightning. Beukeboom was a third-round pick in the 2010 draft by the Lightning.
"We looked at our depth charts and thought he might have a better opportunity with another organization," Armstrong said. "We just decided to let him go back into the entry draft. He's a good young man and we wish him well."