Washington Nationals manager Dave Martinez said Friday the ace could have season-ending surgery due to carpal tunnel syndrome -- a nerve issue in the wrist.

Of course, the injury is commonly brought on by people who spend too many hours at a keyboard ... but Strasburg clearly got it from hurling curveballs and 95 mph fastballs.

Strasburg had complained of tingling and numbness in his hand prior to taking the bump this season ... and ultimately went on the IL last week over the injury after only starting 2 games.

Martinez says the 32-year-old saw a hand specialist this week ... and the Nats got the bad news Friday.

It's a huge blow to the team ... Stras was arguably the biggest reason the Nats won the World Series last season -- and not having him for a postseason run could spell an early exit.