They're confident the right-hander can do so Wednesday night as he tries to continue his success against the visiting Houston Astros, who can overtake the fourth-place Rangers by percentage points in the AL West with a series sweep.
Darvish (8-4, 2.63 ERA) remains on track to pitch even after being struck in the head by a ball in a throwing session during batting practice prior to Texas' 8-3 loss Tuesday. He was examined by the team physician and stated "everything appears to be OK."
The Rangers are expected to re-evaluate him prior to Wednesday's contest.
Though Darvish is 1-2 with a 4.50 ERA in his last four starts, he's 1-0 with a 1.27 ERA and 33 strikeouts in his last three versus Houston (38-54). He allowed a hit and struck out nine in eight innings of a 1-0, 12-inning home win April 11.
Losers in three straight, nine of 10 and 17 of 20, the Rangers (38-52) had won 24 of 27 over Houston before being outscored 33-14 during their four-game series slide. The only other time they were swept in a three-game set by the Astros was at home June 20-22, 2003.
"It's just nice to beat them this year," Houston's Chris Carter said.
Carter homered twice and George Springer added a solo shot Tuesday for the Astros, who have won two in a row following their second seven-game losing streak and are one game behind the Rangers in the West.
Except for a total of just 21 days, the Astros have been at the bottom of the five-team division since joining the AL prior to last season. The last time they were not alone or tied in last place was when they were 3-3 on April 6.
Carter is batting .350 (7 for 20) with four homers and seven RBIs in his last five contests after going 3 for 38 in his previous 12. He's hit .381 in his last five versus Texas, but is 0 for 11 with seven strikeouts against Darvish.
Teammate Jose Altuve had two hits to raise his AL-leading average to .341. Also the league leader with 41 stolen bases, Altuve matched a club record with his 28th consecutive steal without being caught.
He's batting .419 in his last seven versus Texas, but is 2 for 17 against Darvish.
Houston's Dallas Keuchel (8-5, 3.06) needs help to win the final internet vote for a spot on the All-Star team and hasn't looked deserving of the honor while going 0-2 with a 6.50 ERA in his last three starts - all on the road.
The left-hander allowed five runs and a career-high 13 hits in five innings while not factoring in the decision of a 7-6 loss to the Los Angeles Angels on Friday.
"I haven't been too good as of late, so I guess I have to go back to the drawing board and figure some stuff out," Keuchel said.
He was 0-2 with a 4.75 ERA in five starts against the Rangers before tossing a seven-hitter during an 8-0 home victory over Texas on May 13.
Adrian Beltre is batting .378 during a 12-game hitting streak, and .391 (9 for 23) versus Houston in 2014. He's hit .313 (5 for 16) with three doubles against Keuchel since the start of last season.