With three weeks left, the Washington Nationals now face a perennial dilemma for teams that are slipping out of a postseason race or trying to hang on to a .500 season. Do you play your best prospects, who may be crucial to next year's team? Or do you owe it to yourself, and to the other contenders in the race, to put your best team on the field every night until you are eliminated?

Luckily for the Nats, they are in position to do both. Right now, the players about whom the Nats most desperately want answers -- Ryan Zimmerman, Ryan Church, Marlon Byrd and (cue the "Bull Durham" theme) Rick Short -- are also the players who give them the best chance to score runs for a change and maybe make some noise down the stretch.

Regardless of where they finish the season, the Nats can give their fans some entertainment for the next 18 games while gathering valuable intelligence on how to structure their team for next season. If nothing else, the Nats' brass owes it to the team's future owners to garner as much information as possible on key players before offseason free agent decisions are made.

Wasting these last three weeks by playing thoroughly known commodities such as Vinny Castilla, Cristian Guzman, Preston Wilson and (still hobbling) Jose Vidro would be a disservice to both this season and next year as well. Questions need answers.

Will Zimmerman be ready to be a starter next season? And as a third baseman or a shortstop? Let's start finding out.

In his one start at shortstop, Zimmerman made two errors, both by rushing plays and bumbling grounders. The next day, Marlins Manager Jack McKeon said: "I'm impressed by Zimmerman. I like the way he handles himself."

But the two errors, Jack? "I've been watching this game a long time," said the 74-year-old McKeon. "Sometimes, you can tell just by the way they move, the way they react to situations. Zimmerman is going to be good."

At worst, if Zimmerman plays regularly now, it will become clear he needs more seasoning. But this 20-year-old is beating on the door -- hard. Last week, the first time he faced Marlins pitcher Dontrelle Willis, he pounded a ground-rule double over the center field fence; in his first at-bat against Atlanta's John Smoltz, the result was identical. Both would have been homers in most parks. On Sunday, his two-out, two-strike RBI hit in the eighth put the Nats ahead of Atlanta, 7-6. It was a true playoff-chase clutch hit.

Most of the Nats' remaining games are against teams with postseason ambitions. So, most games will be a true test, not a perfunctory September waltz. So, let these four first-year Nats see some of the NL's best pitching with money on the line.

Is Church the graceful outfielder who hit .353 for two months and seemed headed to NL rookie of the year? Or is he the injury-prone player who's taken months to regain his hitting form after running into a wall to save a victory in Pittsburgh? On Saturday, he had two hits in his return from the disabled list. On Sunday, he drove in the game-tying run in the eighth. "I'm dying to get in there and play," said Church, who knows some in the organization have questioned his healing time in the past.

Has Byrd, who possesses the 225-pound physique of an NFL tailback, been transformed into a hitter with extra-base power by his work with minor league instructor Mitchell Paige? Or is Byrd just in an eye-opening hot streak? Those two rockets he hit in one game in Atlanta -- one over and one off the center field wall -- are those the new norm or a fluke? The Nats need to know. "I'm a different hitter now," said Byrd. "A light went on. Now I see how guys like Jose Guillen do it."

"Load and explode, baby, load and explode," said GM Jim Bowden last week as he passed Byrd's locker, repeating a Paige mantra. "People are going to see a whole new Marlon Byrd."

Not if he's sitting on the bench. Not if some new combination of Nationals executives arrives in the offseason and sees a stats line that reflects the old Byrd, who was a Punch-and-Judy hitter.

Finally, let's give the Rick Short Story a chance to play itself out. This guy is the Crash Davis of real life, except he probably never met too many Annie Savoys outside the clubhouses in West Tennessee and Edmonton. Short has a .319 career average in 12 bush-league seasons. He's hit .300 everywhere, including Japan. This season, he hit a nutty .383 in Class AAA.

Deivi Cruz, who has been playing second base instead of Short, couldn't bat .383 if you let him hit the ball off a tee. So, give Short a chance. Nobody else ever has. Since the day he left Western Illinois, the kind of tobacco driveling scouts who were ridiculed in "Moneyball" have said Short doesn't "look" like a big-league hitter.

As a result, Short never got a big-league at-bat until this year. First time up: pinch-hit RBI single. Short never got two at-bats in a game until last week. What did he do? The 32-year-old homered off Willis into the left field mezzanine in RFK Stadium for the Nats' only run in the D-Train's 20th win. For that, what was Short's reward? Three days on the bench, naturally. On Sunday, Frank Robinson graciously allowed him on the field again. So, Short hit a 400-foot home run off Smoltz.

To date, Short has been allowed to bat 11 times -- almost one for every year he's been a pro. So far, he's hitting .333, hasn't struck out and has homered off those bums Willis and Smoltz. With Vidro still gimping too much for Robinson to allow him back at second base, what's the downside in playing Short? What, he's going to screw up The Worst Offense In Baseball?

If nothing else, a Short audition might even bring some good luck to the Nats. After all, the gods never stop watching. Right now, some providential karma and a few new faces in the lineup are the Nationals' last, best hope for 2005.