ARLINGTON -- Baseball plays mean tricks on teams.

Just when the Rangers seemed to have everything going their way, a plague of tightness claimed starter Yu Darvish and third baseman Adrian Beltre on Wednesday.

Darvish and Beltre, central figures on this club, were forced out of the 3-1 loss to Houston at Globe Life Park because of physical maladies. The loss, only the fourth in the last 18 games, became secondary for the Rangers to their conditions.

For Darvish, it was tightness in the right shoulder. Darvish, pitching on the normal four days rest for the first time since undergoing Tommy John surgery, came out after five innings with one run and seven baserunners allowed.

For Beltre, it was tightness in the left hamstring, which grabbed him as he ran the bases in the eighth inning. Beltre immediately headed off the field, a telling sign. Beltre leaves games under only dire circumstances.

Beltre will miss Thursday's game, ending his streak of consecutive starts at 151. Jurickson Profar, who took grounders at third before the game, will start in his place.

"Anytime a player comes off the field, there's concern," manager Jeff Banister said. "I'm not going to overplay it or underplay it in any direction until we get a read on it."

Darvish showed good velocity into the fourth inning, with 18 fastballs at 95 mph or faster. Darvish went 95, 97, 97, 98 in a four-pitch sequence to the heralded Carlos Correa in the third.

Darvish, speaking through an interpreter, said he began to experience neck stiffness during the fourth. At the same time, his velocity began to decrease.

In the fifth, Darvish stayed away from the fastball and threw secondary pitches, such as a 63-mph curveball to strike out George Springer. Darvish kept shaking his arm, often a tell-tale sign that something is wrong.

"I wasn't sure if he was just changing his game plan, or if he didn't feel right," Houston manager A.J. Hinch said.

A walk to Jose Altuve brought out pitching coach Doug Brocail and athletic trainer Kevin Harmon. Darvish stayed in the game after two "test" tosses and threw two more pitches to finish the inning.

"I noticed some body language," Banister said. "A little out of character. It looked like he started to regulate the fastball."

In a dugout conversation after the inning, Darvish mentioned the stiffness. That was enough for Banister to remove him.

Dr. Keith Meister, the team physician, examined Darvish and found nothing out of the ordinary. The shoulder is not involved in Tommy John surgery, which replaces a ruptured elbow ligament. If any part of Darvish is not functioning as designed, the entire Rangers' organization feels the discomfort.

Darvish insisted he is not concerned and hopes to stay with his normal day-after routine by playing catch.

"Everyone told me after the Tommy John surgery, you go through all those small things from different places on your body," Darvish said. "I think it's one of those things, and I'm not too concerned about that."

Darvish lacked the crispness of his previous two starts, in which he allowed two walks in 102/3 innings. He lacked command of the fastball and walked four.

For the fourth time in 86 career major league starts, Darvish received the jarring wake-up call of a homer by the first hitter faced. George Springer drove a 2-0 fastball, at 92 mph, to left.

"The fastball command seemed to come and go," Banister said. "We didn't feel like he was nailing the fastball like he's accustomed to. That made it a little challenging."

The Rangers hope to have a better idea on the condition of Beltre and Darvish in the next 24 hours. They have the best record in the American League at 36-23 but cannot relax.