WASHINGTON -- The Nationals' bench has been historically good, and the thing that excites manager Davey Johnson is that it is likely to soon get better.

The club's pinch-hitters have a .423 on-base percentage this season, the highest mark recorded by a Nationals club since STATS, Inc., began recording pinch-hit stats in 1974.

And with the return of infielder Chad Tracy on the horizon, it could mean even more of a lift off the bench.

Tracy, who is rehabbing with the Class A Potomac Nationals, is working his way back from a torn right groin muscle he suffered on May 26. He is hitting .265 with a .837 OPS this season, with three homers and 12 RBIs. He's 6-for-18 as a pinch-hitter on the year, and nine of his RBIs have come in the pinch.

"I want to get back as soon as possible, and if I feel I can help the team off the bench, I think Davey would want me there," Tracy said.

The bench has fared well in Tracy's absence, with pinch-hitters recording a .292 batting average, with 10 doubles, a triple, two homers, 16 RBIs, 17 walks and 12 runs scored.

Mark DeRosa and Tyler Moore each notched key pinch-hit doubles in Thursday night's 6-5 comeback win against the Giants.

"The bench has been outstanding," Johnson said. "And it's gonna get better when Tracy gets back."

Nats doing their best to deal with soaring temps

WASHINGTON -- Even at home, Stephen Strasburg and the Nationals can't escape the heat.

Temperatures at Nationals Park weren't likely to hit 100 degrees Friday night, but Strasburg nevertheless made his third consecutive start in sweltering heat when the Nats began a three-game series with the Rockies. Triple-digit heat is forecasted for the remainder of the weekend series, with a high of 105 degrees expected for Saturday and 100 for Sunday.

Strasburg's last start came on June 30 in Atlanta, when the first-pitch temperature read 104 degrees. It eventually reached 106, according to multiple media reports. The Nats' young ace lasted just three innings against the Braves -- his shortest start of the season -- and needed three IVs of saline solution after the game. Gio Gonzalez took the mound for the series finale the next day, when it was 101 at first pitch.

Manager Davey Johnson said Strasburg didn't take an IV before Friday night's game, though moving forward, the team could adopt a similar routine to that of the Braves' Tim Hudson, who takes an IV in preparation for his starts.

Following that last start in Atlanta, Johnson said Strasburg had a "pretty scary" moment, when the Nats' young ace looked white in the face and was breathing heavily in the dugout between innings. Later, Johnson said he found out Strasburg "got a little dizzy" on the mound.

"It's tough out there," Strasburg said after that start. "Obviously, I wanted to go out there and compete. I expected a lot more out of myself. By no means was I going out there thinking I wasn't prepared for it. I did everything I could to be ready for it, as far as hydrating. You've just got to learn from it. It's a tough situation."

Johnson did say the medical staff was on hand to administer IVs to any player who needs one before or after Friday's game, which is expected to have a heat index near 100 degrees at first pitch.

Strasburg also dealt with extreme heat on June 25, when the first pitch in Colorado came with the temperature reading 100. He lasted six innings and was charged with the loss after allowing three earned runs on six hits.

Nats' bullpen is tight-knit group on and off field

WASHINGTON -- All you have to do is observe the Nationals' bullpen off the field to know how good they are on it.

Washington has arguably the best pitching staff in baseball -- entering Friday, the club's 3.21 ERA was tops in the big leagues -- and much of that credit has gone to the rotation. The starters have been superb, but so have the relievers.

The seven-man bullpen contained five members working with ERAs below 2.00 heading into the series opener against Colorado: left-handers Sean Burnett (1.47) and Michael Gonzalez (1.64); and right-handers Tyler Clippard (1.78), Ryan Mattheus (1.95) and Craig Stammen (1.74).

"We've got a lot of guys with the same interests, of the same age, and we've all played together for a while," Stammen said. "Those three combinations kind of make us a little tighter. And we've got a group of good guys, too. Nobody's off in the corner doing anything. We all hang out together on and off the field.

"The old saying is the teams that are good off the field are good on the field. And I think that's true for our bullpen."

Manager Davey Johnson said it's gotten to the point where he'll look out to the bullpen with the idea of getting a reliever warmed up, and the pitchers already know what the call is going to be.

That's great chemistry, but he recognizes what it's also meant for the players' production from the mound.

"I think I like this bullpen as good as any I've ever had," Johnson said. "I think the depth in this bullpen and the versatility of this bullpen for different lineups is the best bullpen I've ever had."