(John McDonnell/The Washington Post)

For about 15 minutes prior to Thursday’s contest against Arizona, Nationals Manager Davey Johnson chatted about a series of baseball topics, ranging from bullpens to hitting mechanics. Then, when a reporter asked him who would start on the mound for Saturday’s contest at the New York Mets, Johnson suddenly found himself at a loss for words.

Perhaps unlike a certain New York Yankee, Johnson didn’t want to jump the gun in announcing the starter — a spot left in limbo when Dan Haren was placed to the 15-day disabled list this week.

“I…I…I don’t know when they’re going to name it,” Johnson said. “I’m sure the young man knows he’s coming up here.”

Deductive reasoning led everyone in the room to realize that right-hander Taylor Jordan will be called up from Class AA Harrisburg for Saturday’s start. It should also be noted that the Nationals outrighted right-handed pitcher Ryan Perry to Class AA Harrisburg, which opens a spot on their 40-man roster for Jordan.

On Wednesday, Jordan was named to the U.S. roster for the All-Star Futures Game after impressive showings with Class A Potomac and Class AA Harrisburg this season.

Johnson was less close-mouthed about another player currently on the Harrisburg roster — Bryce Harper.

The outfielder will continue his rehab from left knee bursitis tonight when Harrisburg travels to take on the Bowie Baysox. The plan is for Harper to play an entire game, take Friday off, play Saturday and then rest again on Sunday. Barring a setback, Harper will join the Nationals on Monday when they open a four-game home series against Milwaukee.

Johnson expressed concern over the dampness of the field, an issue that led Harper to serve as the designated hitter in Wednesday’s contest with Potomac where he went 1 for 3 with a home run.

“The only thing tonight, hopefully the field is not going to be damp. I don’t know what kind of field is in Bowie, but Potomac is right there at the bottom of a hill and that field can retain water,” Johnson said. “Ideally, he can run around for 8 or 9 innings and see how he reacts to that.”

Johnson was less worried about Harper’s right foot after the 20-year-old fouled a ball off it in the sixth inning.

“Bunch of mother hens down there,” Johnson said with a smile. “Foul the ball off your foot, coming out of a game. You kidding me? It’s like he was important or something.”