SEATTLE -- Rangers reliever Shawn Kelley thought his career might be over after he felt pain in his right shoulder while warming up on Sunday in Houston. He threw his glove in anger when he went into the dugout.

Turns out, it wasn’t as bad as everybody first though, although he was placed on the 10-day injured with right biceps soreness on Monday. An MRI examination done on Sunday night showed no major structural damage.

“Much better than we anticipated,” manager Chris Woodward said. “When you walk off the mound and throw your glove in the dugout, you think the guy’s season is over. That was my first thought. Something was blown out or his career might be over at his age. Not a cool moment at all, really scary.”

Kelley, 35, has not been 100 percent physically over the past 4-5 weeks and has been trying to pitch through it. He has a 4.35 ERA and a 1.55 WHIP in his last 10 outings while opponents have been hitting .356 off him.

“I was concerned because I never had shoulder problems,” Kelley said. “I was extremely frustrated because that could have been the last time I walked off the field. The MRI revealed no major structural damage, It showed a few things that were aggravated and the way I describe it is there is something in there that is angry at me and I have to let it calm down.”

To replace Kelley in the bullpen, the club called up right-hander Rafael Montero. The Rangers also announced that rookie right-hander Pedro Payano will pitch on Tuesday although Woodward said there is a good chance left-hander Brett Martin could be used as the opener. Payano replaces left-hander Joe Palumbo, who was scratched with right ankle tendinitis.

Kelley goes on the injured list just 10 days before the July 31 Trade Deadline. Clubs are looking to reinforce their bullpens, and both Kelley and right-hander Chris Martin could be of interest.

Kelley has appeared in 32 games for the Rangers and is 5-2 with a 3.00 ERA, 11 saves and a 1.15 WHIP. He had been getting most of the work as the Rangers' closer since José Leclerc stumbled at the beginning of the season. Kelley’s injury could mean Leclerc finally returning to the closer’s role.

Leclerc has a 2.25 ERA and a 1.00 WHIP in his last 16 games. During that stretch, he has held opponents to a .164 batting average with 22 strikeouts in 16 innings. He and Martin are both candidates to be the closer while Kelley is out.

“Either one I am fine with,” Woodward said. “Chris has thrown well all year. It could be Leclerc. It will be at some point.”

Payano has made a combined 15 starts and one relief appearance at Double-A Frisco and Triple-A Nashville, going 5-3 with a 4.40 ERA and a 1.28 WHIP. He is averaging seven hits, 4 1/2 walks and 10.7 strikeouts per nine innings. He pitched one scoreless inning in relief for the Rangers against the Twins on July 6. His 95.8 mph average fastball velocity is the fourth-highest for a Rangers pitcher this year.

The question is whether this is a spot start, or do the Rangers plan to give him an extended look?

“Hard to say,” Woodward said. “It depends on how he throws. It would seem like a spot start, but I like what I saw of him in Minnesota. I don’t know what it’s going to be like after Minnesota, but if he throws well, there could be a chance to make another start.”

Montero was with the Mets from 2014-17, going 6-16 with a 5.38 ERA and a 1.71 WHIP in 30 starts and 28 relief appearances. He missed all of '18 after undergoing Tommy John surgery on March 7 that year and was signed by the Rangers as a free agent this winter.

He has pitched in 11 games between the Arizona Rookie League Rangers, Frisco and Nashville, going 1-0 with a 3.44 ERA and a 1.04 WHIP. At his best, Montero throws 92-93 mph with a slider and changeup as his swing-and-miss pitches.

“He’s throwing good,” Woodward said. “He is throwing really well. I have been hearing his name. People have been telling me how good he has been throwing. He’s built up and throwing multiple innings. He is an interesting guy.”

To make room for Montero on the 40-man roster, the Rangers designated for assignment outfielder Carlos Tocci. He was hitting .246 with a .317 on-base percentage and a .312 slugging percentage at Nashville.

Rangers beat

• The Rangers will have at least three Minor League teams in postseason play. Hickory (Class A South Atlantic League), Spokane (Class A Northwest League) and the Arizona Rookie League Rangers have all clinched playoff spots from the first half.

• Rangers starter Lance Lynn went six innings against the Astros on Sunday. It’s the 16th straight time he has gone six innings, the second longest such streak in the Major Leagues. Clayton Kershaw of the Dodgers has gone at least six innings in his last 17 starts. The longest in Rangers history was 27 straight by Kevin Brown in 1992.

• Montero will be the 23rd reliever used by the Rangers this season. That doesn’t count catchers Jeff Mathis and Todd Federowicz, who were used in mop-up situations.