The Texas Rangers made a surprising announcement Monday afternoon: Right-hander Nathan Eovaldi would not pitch because of discomfort in his left side.

ARLINGTON — Nathan Eovaldi will not start for the Texas Rangers on Monday night after complaining of discomfort in his left side shortly after arriving at Globe Life Field for the opener of a three-game series against Arizona.

The Rangers selected right-hander Jakob Junis to start the game as an opener, and manager Skip Schumaker said he will likely treat the situation as a more traditional bullpen game rather than using a bulk pitcher behind Junis.

Eovaldi was sent for an MRI exam, the results of which are pending.

“It didn’t feel real smart sending him out there,” Schumaker said. “You never want to hear left-side anything from anybody. So, we’ll find out when the imaging comes. I don’t want to guess what it is.”

Eovaldi is 4-4 with a 4.15 ERA this season, numbers that were buoyed by his last two starts. He allowed only one run in 15 innings against the Yankees and delivered for the Rangers their only win in each three-game series.

After allowing 11 runs in his first two starts of the season, Eovaldi has a 2.54 ERA in his past six starts.

Junis has been a starter or swing man for most of his career, and last season was the first of his career in which he didn’t make a start. Schumaker said he doesn’t expect more than two innings from the right-hander, who has two saves this season.

The Rangers were still game-planning how they would deploy relievers after Junis is done. Schumaker said that all relievers are available. There’s also the possibility that the Rangers could recall right-hander David Davalillo from Double A Frisco if Eovaldi needs to go on the injured list.

Frisco is off tonight and was rained out Sunday on Davalillo’s turn to start.

If the Rangers need a starter with more experience, they could turn to long man Cal Quantrill, Triple A Round Rock left-hander Austin Gomber or Round Rock righty Trey Supak.

Jeff Wilson, jwilson@alldlls.com