Seattle Sounders FC forward Clint Dempsey returned to training on Wednesday after being sidelined last month with an irregular heartbeat, the club announced on Wednesday.

Sounders GM Garth Lagerwey told reporters that Dempsey underwent an unspecified procedure to address some of the issues surrounding the irregular heartbeat.

For that reason, Dempsey is being restricted to light training, and hasn't been cleared to play. Lagerwey added that he was "cautiously optimistic" that Dempsey would be able to return to play by the end of the season, but that there was no timetable for the player's return.

"One of the important things here when you have a medical condition like this, you don't want to put false pressure on a return," Lagerwey said.

"You can't just say, 'Clint's important to us.' You have to mean it, and if you mean it that means Clint's health comes first, and that means there is no timetable by definition, because you have to wait and see if or when Clint is healthy and ready to come back to a full return."

Lagerwey earlier told the Times that Dempsey has been dealing with the symptoms for much of the season. Dempsey last played in the Sounders 3-1 win over the Portland Timbers on Aug. 21.

He then sat out the Aug. 24 match at Houston before the Sounders announced two days later that the U.S. international would be sidelined indefinitely in a bid to get to the root of his symptoms.

Clint Dempsey has been restricted to light training after returning to Sounders practice. Kim Klement-USA TODAY Sports

In addition to missing three games with the Sounders, Dempsey also sat out both of the recent World Cup qualifiers the U.S. played against St. Vincent and the Grenadines and Trinidad & Tobago.

While the team's caution is understandable, interim manager Brian Schmetzer said that the entire team was lifted by Dempsey's presence.

"I'm just really happy, the players are really happy, it was like good news for us, and you could see that that translated into the tempo of training today," Schmetzer said.

Schmetzer later added: "[Dempsey] was in great spirits and the team was obviously lifted by him being here."

Dempsey is in his fourth season in Seattle, and currently has eight goals and two assists on the season.

All told, Dempsey has 37 goals and 23 assists in 82 regular season and playoff appearances. Dempsey has also played for English sides Fulham FC and Tottenham Hotspur, as well as the New England Revolution of MLS.

Dempsey has scored 52 goals for the U.S. national team in 130 appearances.