WASHINGTON — The Washington Nationals found perhaps the only pitcher who can trump Roy Halladay's debut with the Philadelphia Phillies.

He's a lefty without a whole lot of experience, and one of his big recent victories came by the eye-popping score of 219-212.

Of course, that was a health care vote in the House of Representatives, not a baseball outing. The left-hander is President Barack Obama, who will mark the 100th anniversary of presidential first pitches by performing the ceremonial duty Monday at Nationals Park.

"I'm going to be talking to him in the cage. I'm going to be warming him up," Nationals catcher Ivan Rodriguez said. "I'm going to take a picture with him, if he'll let me. It'll be exciting."

Cool customer Ryan Zimmerman gets the honor of catching the actual first pitch — "It's just a pitch. I've met Bush and those guys before," he said — and the Gold Glove third baseman might need to exhibit his best range to save the Commander in Chief some embarrassment. Obama didn't grow up playing organized baseball and nearly bounced his only previous presidential first-pitch attempt at the All-Star Game in St. Louis last year.

"I'll do my best," Zimmerman said. "I can't promise anything, but I'll do my best."

Once the pageantry is done, the focus turns to Halladay, the centerpiece of the Phillies' bid to win their third straight National League pennant and second World Series in three years.

After 12 seasons with the Toronto Blue Jays, the six-time All-Star and 2003 Cy Young Award winner has an extra skip to his step for this opening day.

"It's more exciting. The whole spring has been that way," Halladay said. "It's nice to have that spring to get acclimated. I'm looking forward to the season as a whole more than I have in the past. It's a lot more exciting for me knowing this is a competitive team looking to win."

If the Phillies are "a competitive team looking to win," the Nationals are a team simply looking to be competitive after back-to-back 100-loss seasons. There have been some upgrades — Rodriguez among them — but the franchise rests in a sort of holding pattern while awaiting the expected June arrival from the minors of Stephen Strasburg, last year's No. 1 overall pick and the projected opening day starter in 2011 and beyond.

Holding the seat warm in the meantime is John Lannan, getting the opening day nod for the second straight season. The 25-year-old left-hander admits he didn't cope very well the so-called "ace" label in 2009.

"Last year, I kind of struggled opening day. It was new to me. I tried to do too much, I think," Lannan said. "This time around, it's going to be exciting. It's home. I'll go out there and throw as if it's a regular game — which it is, you know?"

Well, not really.

Opening day is one of the few dates the Nationals can actually fill their ballpark, and having Obama on hand adds to a distinctly Washington spectacle that began when President William Howard Taft made a ceremonial toss to Hall of Fame pitcher Walter Johnson in April 1910.

The cherry blossoms are in bloom this time of year in the nation's capital, making the city as bright and cheerful as a baseball fan on the first day of the season.

Zimmerman tossed in his own bit of Nationals optimism when asked if Obama's appearance might be an effective way to steal some of Halladay's thunder.

"Well," Zimmerman said, "Lannan might be able to, actually."

___

AP freelance writer Ken Mandel in Philadelphia contributed to this report.