HOUSTON -- Hunter Pence likely will slot into the Rangers' lineup as the designated hitter for at least another week while he continues to reacclimate himself after a somewhat lengthy stay on the injured list with a right groin strain.

Pence, who completed a five-game rehab stint with Double-A Frisco before rejoining the Rangers after the All-Star break, has played 31 games at DH and 20 in the outfield this season. While the DH spot won't be an immovable, permanent assignment, it provides a good opportunity for Pence to continue to get his legs under him after missing 23 games with the injury.

Strength-wise, Pence said he felt like he was at his best during the series opener Friday at Houston. The results reflected that -- he was 2-for-4, marking his first multi-hit game since June 13 at Boston.

"I haven't been able to run that fast until yesterday," Pence said Saturday. "It's still not 100 percent, but it was a lot better. The fact that it's getting better as I play, that's a good place to be."

That's good for the Rangers' big-picture outlook, too. They're hanging on in the American League Wild Card race, but if they're to stay in contention, a lot has to go right, including being able to rely on a potent offense that contributed to a strong first half.

It's fair to surmise the Rangers would not be in this position without Pence and his .291 average, 15 homers and 48 RBIs. He's going to play every day, even if it means less flexibility in finding at-bats for several key members of the lineup.

"It makes it a little harder, but you also have Pence in the lineup, which is a good thing," manager Chris Woodward said.

Rotation shuffle, again

Before the series opener in Houston, lefty Joe Palumbo was announced as the starting pitcher for Monday at Seattle. One day later, that plan was scratched, due to Palumbo coming down with minor tendinitis in his right ankle after feeling discomfort while throwing a simulated game on Friday in Nashville.

Right-hander Adrian Sampson will be bumped up a day and start Monday. The Rangers have not yet decided on a Tuesday starter, though Woodward mentioned right-hander Pedro Payano as an option.

If that is the case, the Rangers may use an opener to get things started on Tuesday and peg Payano for the second inning and beyond.

The fluid rotation situation will stabilize after that, with rotation anchor Mike Minor scheduled to take the mound for the finale in Seattle on Wednesday.

Kiner-Falefa to Double-A

Catcher Isiah Kiner-Falefa was activated from the 10-day injured list on Saturday and optioned to Double-A Frisco, where the Rangers plan to give him ample playing time, both at third base and catcher.

Consistent at-bats are the key factor regarding Kiner-Falefa, who has been sidelined since June 7 with a right middle finger ligament sprain. Finding enough reps for him at the Major League level would be more challenging.

Woodward estimated Kiner-Falefa will be with Frisco for at least a week.

"We all love the guy," Woodward said. "We want him here. I know he's been grinding so hard when he comes here, and his offense kind of took a backseat to a lot of the catching stuff. This allows him to get those at-bats he was missing, to build up some momentum, so when he comes back he's in a good place offensively."

Fifty years ago today

We all know what was happening in space on Sunday, July 20, 1969, exactly 50 years ago. But while the Apollo 11 lunar module was landing on the moon, what was happening in baseball -- and, more specifically, with the expansion Washington Senators?

Right at 3:17 p.m. ET, when Neil Armstrong took the first step onto the moon, the Senators, who moved to Texas after the 1971 season, were playing the Yankees at New York. That game started a little over an hour before Armstrong's moonwalk, at 2:02 p.m. ET. The Yankees defeated the Senators, 3-2 in 11 innings, on a walk-off single by Gene Michael off Casey Cox. That was Ted Williams' first year managing the Senators.