Clint Dempsey said on Tuesday that he is back to 85 or 90 percent of full fitness ahead of the start of the 2017 Major League Soccer season.
Dempsey, 33, missed the end of the 2016 season -- including the Sounders' MLS Cup victory over Toronto FC and the start of World Cup qualifying for the United States -- after being diagnosed with an irregular heartbeat last August.
But The U.S. international said he's feeling good again and looking forward to being back with the Sounders.
"It was a heart issue. It's something that's difficult to kind of explain,'' Dempsey told reporters after training on Tuesday. "But at the same time I'm not feeling those things anymore and I'm happy to be back playing.''
Dempsey said he first noticed symptoms last February during training camp and spent the early part of the season trying to figure out what was happening. He said he felt fine playing for the United States during the Copa America last summer, but after returning from the competition started "feeling more stuff.''
He was first announced to be out of action on Aug. 26 because of the irregular heartbeat, two days before Seattle faced rival Portland. He never played again last season, although there was optimism in September that he might have a chance to return.
He was officially ruled out for the season in late September after undergoing an undisclosed procedure.
"I was experiencing the same issues that forced me off to do the right thing and give my body the right rest and making sure that I would be better,'' Dempsey said. "That's what I had to do, I had to take the time off and now I'm not experiencing those issues anymore.''
The 33-year-old remained guarded about any specifics regarding his heart condition saying: "I don't really want to go that much into it.''
But he has been cleared for a progressive increase in his workload.
Dempsey has been a full participant in practices and had stints of 30 and 45 minutes in preseason games in Arizona recently. That workload is expected to increase as the Sounders leave later this week for the final stage of their preseason training in South Carolina.
Dempsey estimated he's now about "85 percent, 90 percent back to full fitness" after starting a closely monitored exercise regime before training camp.
"I was able to consistently progress and work on my fitness and make sure everything was moving in the right direction,'' Dempsey said. "It started off slow and had to work my way up and still working up now but feeling like I'm finally getting close.''
Dempsey is also hopeful of working his way back into consideration for the U.S. national team. He said he spoke with Bruce Arena late last year about everything that was going on.
"It would be great to get back in with the U.S. team but to do that I have to do well here and that's the main focus, is here with Seattle and making an impact on the field here,'' Dempsey said.
Information from the Associated Press was used in this report.