ARLINGTON -- The Rangers' starting rotation sunk into further disarray Tuesday, as struggling right-hander Jason Jennings was forced to leave because of new pain in his surgically repaired throwing elbow in the third inning of a 9-5 loss to the Royals.

Jennings had surrendered five runs on eight hits and thrown 53 pitches when he became alarmed by what he called a "sharp twinge" in the back of his elbow. He had just thrown a changeup that was smacked by Ross Gload for a leadoff single in the top of the third.

"I wasn't sure if it was just a one-time thing, so I threw a fastball for my first pitch to the next guy [Miguel Olivo]," Jennings said. "I felt it again, and it was a pain I'd never felt before. That one tonight felt really weird."

Jennings summoned Jarrod Saltalamacchia to the mound, and the Texas catcher quickly called for supervisory help. After relating his sensation to Rangers manager Ron Washington, pitching coach Mark Connor and trainer Jamie Reed, a disconsolate Jennings trudged off the mound still winless in 11 starts since last July 24.

Six starts into his one-year, $4 million free-agent contract signed with the Rangers last winter, the Dallas native is 0-5 with an 8.56 ERA. Jennings has given up 27 runs -- 26 earned -- on 35 hits and 18 walks in 27 1/3 innings.

Rangers orthopedist Dr. Keith Meister examined Jennings after the game, and the team announced an initial diagnosis of an irritated ulnar nerve. The pitcher will be reexamined Wednesday, but no MRI scan was planned.

"I don't know much," Jennings said. "We'll just see how sore I am [Wednesday]."

Jennings, 29, was limited to 19 games and went 2-9 last year for the Astros in a season marred by elbow trouble. He was on the disabled list twice in 2007, first for tendinitis in his right elbow flexor, then for season-ending surgery in late August when that tendon was found to be torn. The pain he experienced Tuesday is in a different part of the elbow.

Texas already is down three starting pitchers. In the past eight days, left-hander Kason Gabbard (back) and right-hander Luis Mendoza (shoulder) landed on the disabled list. They joined right-hander Brandon McCarthy (forearm strain), who started the season on the DL and is expected to be out at least through the All-Star break.

The Rangers are attempting to plug one gap with veteran journeyman Sidney Ponson. They had hoped to use right-hander Scott Feldman for a spot start this Saturday in Oakland, but that plan may have unraveled when Feldman had to throw 69 pitches to cover four innings in relief of Jennings on Tuesday.

Jennings said he is uncertain when he might pitch again.

"I have no idea," he said. "It's sore right now. I guess we'll just come in [Wednesday] and see how I feel.

"I think that if the doctor felt it was something serious, he would want to schedule an MRI right away, but I don't know. We knew there would be some peaks and valleys this year coming back from surgery. Hopefully, this is just a bad day."

Meanwhile, most of the initial crowd of 16,472 at Rangers Ballpark had left before the team's 14th loss in the last 18 games became official. The Rangers (9-18) have lost nine of 11 to fall a season-high nine games under .500.

Kansas City jumped to a quick 5-0 lead in the first two innings, with what appeared to be some help from home-plate umpire Bill Welke.

On a close play at the plate with one out in the first, Welke ruled that Mark Grudzielanek was safe. Replays indicated Saltalamacchia had tagged Grudzielanek on the hip before his toe reached the plate. Despite Washington's protests, the call stood and helped trigger a three-run inning for the Royals.

"It probably had an effect," Washington said. "He ended up blowing the call, really."

Saltalamacchia agreed, saying, "We got him out, and [Welke] just missed it -- that's all. But that was only one run."

It set a bad tone for the Rangers for the rest of the game. Still irritated by the call, Rangers second baseman and leadoff hitter Ian Kinsler lost his temper in the bottom of the first. Kinsler took a full-count pitch from Royals pitcher Brett Tomko and started toward first base, only to be called out on strikes by Welke. Within seconds, Kinsler was ejected for arguing.

The Royals pounced. Jose Guillen lashed a two-run single off Jennings to make it 5-0 in the second. Josh Hamilton and David Murphy drove home runs to get the Rangers within 5-2 in the third, but Guillen crushed a two-run homer off Feldman to make it 7-2 in the top of the fourth.

Guillen's blast was estimated at 400 feet, and it was believed to be the first home run to land in the Lower Suites level at Rangers Ballpark.

Tomko was chased after throwing 89 pitches and coughing up five runs on seven hits in 3 1/3 innings. Run-scoring hits by Saltalamacchia, Ramon Vazquez and Michael Young ended Tomko's night, but former Rangers left-hander Ron Mahay (1-0) worked 2 1/3 scoreless innings to pick up the win in relief.

The Rangers brought the potential winning run to the plate in the bottom of the seventh, when Saltalamacchia faced Royals reliever Ramon Ramirez with two on and two outs. Saltalamacchia fouled out to catcher Olivo to end that threat. Royals right fielder Mark Teahen then put things out of reach with a two-run triple in the eighth off Joaquin Benoit.

"We kept coming and kept coming," Washington said. "But it seemed like every time we did, they'd score more runs."