SEATTLE – The Seattle Sounders announced Friday that Clint Dempsey is undergoing medical evaluations for an irregular heartbeat and that the star striker will be held out of the team’s matchup against the Portland Timbers this weekend as the medical process unfolds.

No other details about Dempsey’s health or playing status were released.

Dempsey, 33, has scored eight goals and added two assists this season, including five goals and an assist over the team’s current five-game unbeaten run. He scored two goals in the team’s 3-1 win over the Portland Timbers on Aug. 21 last weekend before sitting out the team’s 1-1 draw against the Houston Dynamo on Wednesday.

The Sounders take on the Timbers at Providence Park in the teams’ final regular season matchup of the year on Sunday (2 p.m. PT; ESPN/KIRO 97.3 FM/El Rey 1360AM).

A spokesman for U.S. Soccer also confirmed to ESPN's Jeff Carlisle Friday that Dempsey will not be called in for the U.S. national team's upcoming World Cup qualifying matches on Sept. 2 and 6.