The Roadrunners' search for a new head coach will begin immediately, after 2018 coach Mike Van Ryn left Wednesday for the NHL's St. Louis Blues.

Tucson Roadrunners coach Mike Van Ryn is leaving the team to join the St. Louis Blues' coaching staff. 

Van Ryn replaces Daryl Sydor, who has stepped down to spend more time with his family. The Blues made the announcement Wednesday afternoon. 

"We are very excited to have Mike joining our staff," Blues head coach Mike Yeo said. "I spoke with a number of people about the position but it was clear that Mike's energy and philosophies were the best fit for our team."

The Roadrunners confirmed Van Ryn's departure earlier Wednesday, but said only that he was  leaving the team "to pursue an NHL coaching opportunity." The club will begin a search for a new head coach immediately. 

“On behalf of the entire organization, I’d like to thank Mike for everything that he did for the Roadrunners last season,” Roadrunners general manager Mike Sullivan said. “We wish him and his family all the best in the future.”

Van Ryn led the Roadrunners to a 42-20-5-0 record in his first — and only — season in charge, and the club claimed the AHL's regular season Pacific Division Championship.

The Van Ryn-to-St. Louis rumors began circulating during the AHL playoffs, when the first-year coach led the Roadrunners past the San Jose Barracuda in the first round before falling to the Texas Stars in five games.

Van Ryn, 39, came to Tucson following one season with the NHL's Coyotes as a player development coach. He is familiar with St. Louis, however: He spent four seasons as a player before latching on with the Florida Panthers. He played 353 NHL games before retiring in 2009.

Van Ryn's departure means the Roadrunners will search for their third head coach in as many seasons. Mark Lamb coached the team in the 2016-17 season.