Selected 19th overall by Winnipeg in 1990, the 6-foot-2, 232-pound Massachusetts native scored 50 goals with the Jets in 1995-96, then a career-best 52 the following season after the franchise relocated to Phoenix. Tkachuk also will be remembered for having a nasty streak, topping 200 penalty minutes three times to become one of the league's most physical forwards.
Despite playing only nine seasons with the Blues (39-32-9), Tkachuk is seventh on the club's all-time list with 425 points. He also suited up briefly with Atlanta in 2007, and has 538 goals, 525 assists and 2,219 penalty minutes overall.
"I have been privileged to have a long career in this terrific league and play for first class organizations," the 38-year-old Tkachuk said.
In January, the five-time All-Star and four-time Olympian became the fourth player in NHL history with 1,000 points and 2,200 penalty minutes. He needs one point to move past Joe Mullen into sole possession of fourth place all-time in scoring among players born in the United States.
"Keith is a true warrior who had an excellent career and I was hoping this day would never come," Blues president John Davidson said. "The NHL is losing an individual who gave a lot of time and dedication to the game and I wish him and his family a happy retirement and the best of luck."
Days after playing in his 1,200th NHL game, Tkachuk announced his retirement Wednesday while sitting out with a lower-body injury in the Blues' 6-5 loss to playoff-bound Chicago. St. Louis trailed 6-1 before scoring the final four goals, including three in the third period.
"If anything, he gives us more to play for," said teammate David Backes. "He was a warrior for 19 years in this league. It was almost semi-disrespectful that the night he says he's going to retire that we put the sort of effort we did in the first half of the game."
Tkachuk's final game will be Saturday in Nashville.
Anaheim, out of the playoffs for the first time since 2004, is 2-1-0 against the Blues this season, including a 4-3 shootout win Jan. 23 at Scottrade Center.
The Ducks (38-31-11) are coming off a 3-2 shootout loss to Dallas on Friday -- the fourth straight game in which they have been involved in a tiebreaker. Bobby Ryan scored his team-leading 33rd and 34th goals and Jonas Hiller stopped 49 shots, including nine in overtime.
"With the youth we have around us, it gives us an opportunity to look at some of our future players, potentially," coach Randy Carlyle told the Ducks' official Web site. "Just see where they are as far as their level of play and their execution at the NHL level."
Anaheim closes out its season Sunday at home against Edmonton.