ARLINGTON, Texas -- Something likely will have to give Thursday when the Rangers and Philadelphia Phillies close out their three-game series with Texas looking to extend an eight-game winning streak.

Rangers left-hander Martin Perez (1-5, 3.89 ERA) hasn't won a start since April 9, dropping his last four decisions despite pitching well recently. Philadelphia rookie right-hander Nick Pivetta (0-2, 6.14 ERA) is still looking for his first big league win after making his debut April 30 and going winless in his first three starts.

While Perez hasn't been able to scratch out a win, he has been solid in May, posting two quality starts in his two outings. He is 0-1 with a 2.92 ERA in May, yet he shares the American League lead with five losses on the year.

"I feel good," Perez said. "When the things aren't going good, you have to try something. You have to see what happens with new things that you want to try. Now I feel good, and I think that's the way I have to pitch. My sinker, my changeup and the pitches I have, I don't need to try and be perfect. Just throw the ball, and I've got good players behind me that are going to have to make the plays."

Perez also hopes to build off the solid momentum the Texas rotation has going. The Rangers lead the AL in quality starts with 26. Seven of them have come in the last nine games, and the Rangers have the best rotation ERA in the majors at 3.35.

Perez would like to keep that going against a Philadelphia team that he has faced just once in his career, getting a no-decision in 2014 after allowing two runs in 5 2/3 innings.

"Nobody believed in us, and I think this time we're doing a great job and I think we're going to continue to do the same job or better," Perez said. "We've got a good team, good teammates. When you have that on one team, that relationship, it's good."

Pivetta's best start was his debut, when he allowed two runs in five innings at Dodger Stadium on April 30. He has allowed four runs in each of his last two starts, including a 6-4 loss at Washington on Saturday in which he lasted just 4 2/3 innings and walked four.

Pivetta has been a valuable member of the pitching staff even though he is slated to be sent to Triple-A following his Thursday start. With early-season injuries to rotation members Zach Eflin, Clay Buchholz and Aaron Nola, the bullpen has been taxed and the rotation stretched.

Pivetta has helped ease that burden, and so will the return of Nola, who likely will come off the disabled list Sunday to take Pivetta's rotation spot. Nola is recovering from a lower back strain. The Phillies won't have to juggle with their rotation so much, and things should settle down for a pitching staff that has the second-highest ERA in the major leagues (4.82).

"We've had to fiddle around and try to give guys extra days (off)," Philadelphia manager Pete Mackanin said. "That's when Pivetta stepped in. So that allowed us to move Nola back to Sunday. We're going to get to the point where we can have our starters pitch every fifth day instead of every sixth day. That might have something to do with their struggles."