Stephen Strasburg has had two MRIs since he was removed from Saturday's game at Philadelphia. (Manuel Balce Ceneta/Associated Press)

Stephen Strasburg had to get through a few hours of anger, confusion and certainly a few more volatile emotions before he was ready to accept the sobering news expressed in three disheartening words.

Tommy John surgery.

The Washington Nationals rookie sensation is done for the season — and maybe next season as well — after the team announced Friday that he has a torn ligament in his right elbow. He will travel Saturday to the West Coast for a second opinion, but the 22-year-old right-hander has accepted the fact that he will need the ligament replacement operation that requires 12-to-18 months of rehabilitation.

"It's a new challenge," Strasburg said. "I want to be the best at everything, and right now I want to be the best at rehabbing and getting back out here."

It's a blow to Strasburg, of course, and to a baseball world that has spent the summer gasping in awe at his 100 m.p.h. fastball, bending curves and wicked batter-freezing change-ups, but the biggest punch to the gut is to a Nationals franchise that had made the young phenom the centrepiece in their plans to climb out of perpetual last-place irrelevancy.

"There's no words that I can put in place here that would indicate we could possibly replace Stephen," manager Jim Riggleman said. "But we have to do it a different way, different names, different staff members who will go out there and fulfil the rotation until Stephen comes back."

Strasburg grimaced, grabbed and shook his wrist after throwing a 1-1 change-up to Domonic Brown in Philadelphia on Saturday. It turned out to be his last pitch of the year. The Nationals initially called the injury a strained flexor tendon in the forearm, but an MRI taken Sunday raised enough questions for the Nationals to order a more extensive MRI in which dye was injected into the prized right arm.

Strasburg had the exam on Thursday and was informed of the diagnosis later that night, but the Nationals chose not to announce the news until because it would have upstaged the introductory news conference for 2010 No. 1 draft pick Bryce Harper.

Arm felt fine

Strasburg could hardly believe the bad news, especially because his arm has felt fine all week, certainly good enough to keep pitching.

"I didn't take a matter of minutes" to sink in, he said. "I took definitely a few hours. I've got great support all around me, and they reminded me of everything I should be thankful for, and they put everything in perspective for me. Bottom line, this is a game. I'm very blessed to play this game for a living. It's a minor setback, but in the grand scheme of things it's just a blip on the radar screen."

Tommy John surgery, so-called because the former pitcher was the first to undergo it, involves grafting an ulnar collateral ligament taken from elsewhere in the body onto the damaged area.

"I look at the bright side," Nationals general manager Mike Rizzo said. "Tommy John surgery is a surgery that we've had great success at. The success rate for guys coming back from Tommy John and retaining their stuff is very good."

Strasburg was pulled from Saturday's game at Philadelphia when he grimaced and shook his wrist after throwing a changeup.

Rizzo said doctors believe Strasburg hurt himself on a particular pitch, as opposed to a gradual buildup. When Strasburg grimaced in the game at Philadelphia, he told the team he had felt something similar at San Diego State and had continued to pitch through it.

Unrelated to previous injury

Doctors have decided that what happened in college was unrelated to the ligament tear.

Even so, Strasburg has been saying this week he is strong enough to pitch.

"Stephen felt pretty good and still feels OK," Nationals president Stan Kasten said. "And that's why this has been so confounding."

The No. 1 overall pick in the 2009 draft, Strasburg signed a record $15.1 million US contract a year ago. He struck out 14 batters in a sensational major league debut in June and is 5-3 with a 2.91 earned-run average and 92 strikeouts in 68 innings.

But he has had medical setbacks along the way, despite the team's best efforts to be as cautious as possible with their prized youngster.

Strasburg was placed on the disabled list a month ago with inflammation in the back of his right shoulder.

He was making his third start since returning from the DL when he had to leave the game against Philadelphia.

"The player was developed and cared for in the correct way, and things like this happen," Rizzo said.

"Pitchers break down, pitchers get hurt and we certainly are not second-guessing ourselves. … Frustrated? Yes. But second-guessing ourselves? No."