The Earthquakes will open camp for the 2015 season next week without Sam Cronin, a holding midfielder who has been a regular for much of the past four years.

San Jose continued its rebuilding effort by sending Cronin to the Colorado Rapids in exchange for allocation money, the team announced Monday.

“We felt it was a good idea to open a roster spot and hopefully land another player in a different area,” coach Dominic Kinnear said. “We’re a little more flexible to go out and get somebody we couldn’t get two weeks ago.”

Kinnear, hired in the offseason to rebuild the Quakes, declined to say where the club would focus attention, but some suggest it could use depth on the back line.

Cronin had five goals and 12 assists in 140 games during four-plus seasons with the Earthquakes. He was San Jose’s most valuable player in 2013.

“When you enter the league you know the business aspect of it,” Cronin said Monday.

With the Rapids opening camp Thursday, the midfielder was scrambling to make the move. He and his wife have a 2-month-old son.

“The timing seems to be a bit strange, but any player can be moved at any time,” said Cronin, who added he will miss his time in San Jose.

Cronin, 28, is the latest veteran let go under Kinnear, who replaced Mark Watson. Cronin follows the departures of goalkeeper Jon Busch, defender Jason Hernandez and midfielder Atiba Harris.

He became expendable last week when the Quakes chose Michigan State midfielder Fatai Alashe with the No. 4 overall pick in the Major League Soccer draft. Kinnear described the rookie as a “box-to-box guy,” meaning Alashe can cover much of the field.

The Quakes had expected Cronin to fulfill that role last year when teamed with French midfielder Jean-Baptiste Pierazzi. But the combination did not produce the desired results for a team that struggled to score.

San Jose also sees promise in second-year holding midfielder JJ Koval, of Stanford.

Kinnear said the team didn’t draft Alashe with an eye toward trading Cronin, however. The coach said the Quakes entertained offers for Cronin from a couple of MLS teams after the draft.

“Knowing you have some youth and potential in that area” made it easier to let go of Cronin, Kinnear said. But, he added, “It’s a tough one.”

Cronin came to San Jose in June 2010 in a trade with Toronto FC. He played a pivotal role in helping the Quakes reach the MLS Cup playoffs in 2010 and ’12.

Toronto made Cronin, a former Wake Forest star, the No. 2 overall pick in the 2009 draft. He is excited to be mentored by Rapids coach Pablo Mastroeni, one of the best holding midfielders in MLS history.

“He’s a player that garners respect from opponents and teammates alike because of his competitive mentality and his will to win,” Mastroeni said on the team’s website. “Sam brings a sophisticated level of play along with leadership qualities which will raise the standard of our entire group as we continue to build for 2015 and beyond.”

Cronin rejoins former San Jose teammate Bobby Burling, who also has been acquired by Colorado in the offseason.

“We’re looking to have a strong rebound season,” Cronin said.