Two years ago, after the longest season of his long career, Landon Donovan returned to his Manhattan Beach home, drew the curtains, turned off the phone and spent two weeks trying to recover.

He eventually emerged from his sequestration to have one of his finest Major League Soccer seasons in 2011, leading the Galaxy with 15 goals, including the score that gave the team its first title in six years.

Exhausted again, Donovan will go back into hiding after Saturday’s MLS Cup final, his 49th game in 48 weeks. Only this time he says he’s not sure he’ll return.

“I’m going to take as much time as I need and decide if and when I’m ready to come back,” he said. “I can’t put a time frame on that. If it takes two weeks and I’m ready to go again or two months or a year or two years.

“Or never. I don’t know.”

Which means Saturday’s game, in addition to being David Beckham’s last competitive match in a Galaxy uniform, could also be the last in Donovan’s storied career, one that has seen him start more games, score more goals and record more assists than any player in national team history.

If he walks away now, he’ll do so as arguably the greatest U.S. soccer player of all time. And he’ll do so with no regrets.

“I’m aware of what I’m feeling, what I’m going through,” he said. “And if I wake up one day and I say ‘you know what? I’m going to come back and play,’ then I’ll be here within an hour. If that doesn’t happen, if I wake up and I say ‘you know what? That’s enough,’ then I’ll let the people know who need to know and I’ll get on with my life.”

In recent years, late-season weariness and career reflection have become a fall tradition for the 30-year-old Donovan. But this time is different, because in addition to fatigue he has also battled knee and hamstring injuries this season. And given Donovan’s serious, often introspective nature, some close to the Galaxy say that has led to bouts of uncertainty.

He has done little to mask those feelings. Four months ago, Donovan said he would consider retiring when his MLS contract expires after next season. Then last month he changed that, saying he wasn’t sure he’d sure he’d make it that far, questioning whether he’d be ready to play when the final round of World Cup qualifying begins in February.

National team Coach Juergen Klinsmann responded by praising Donovan’s honesty.

“I find it very courageous of him to talk openly about what is going through his mind,” Klinsmann said. “I can understand all those thoughts. . . . He’s carrying this topic with him since quite awhile.

“Whatever he decides to do will be very respected by us.”

It’s clear that Klinsmann sympathizes with Donovan since he, too, dealt with similar mental and physical fatigue during a 17-year playing career. But few have ever endured a heavier workload for a longer period than Donovan, who has averaged a game every eight days for the last 12 years — including 313 MLS games and 144 caps with the national team. And he has played in competitions on six continents, including the Olympic Games, World Cup, English Premier League and CONCACAF Champions League.

“What we’re faced with now is a 30-year-old elite athlete that started [playing] at 16,” said Dave Sarachan, the Galaxy’s associate head coach. “So he’s accumulated a lot of minutes and miles. Eventually things start to wear down and it’s new to Landon. Mentally it was a hard year for Landon from that standpoint.

“But when he’s been healthy he’s been the most influential player we’ve had.”

And that’s what head Coach Bruce Arena expects he will be Saturday against the Houston Dynamo, when a win would give Donovan a record fifth MLS title.

“Landon’s been outstanding at times,” Arena said of his captain, who was second in the league with 14 assists and is a good bet to make the MLS First XI, the postseason All-Star team that will be announced Monday. “The month of July he was probably as good as any player in the history of this league.

“That’s what separates Landon from other players. He should make a difference in games.”

As for what happens after that, Arena is leaving that up to Donovan. But at least one teammate believes there’s a good chance the Galaxy’s star playmaker will still be mulling his future when training camp starts in February.

“I wouldn’t be surprised,” said defender Todd Dunivant, who has played eight seasons alongside Donovan. “Let’s be honest, he’s the best American to ever play. And he’s been doing it since he was a teenager. That’s difficult.

“If he needs time to step away, if he’s going to step away for good, that’s up to him.”

kevin.baxter@latimes.com