The Giants on Monday announced disconcerting injury news on two pitchers who were expected to factor into their Opening Day roster plans this year.

Following the Giants’ 6-1 loss to the Royals at Surprise Stadium, manager Gabe Kapler said Rule 5 Draft pick Dedniel Núñez has been diagnosed with an ulnar collateral ligament sprain in his right elbow, an injury that is often a precursor to Tommy John surgery. It could be a significant setback for Núñez, who was making a strong case for a spot in the bullpen this spring, but Kapler said the 24-year-old reliever will seek a second opinion before determining a course of treatment.

Left-hander Alex Wood, who was projected to start the season in the Giants’ rotation after signing a one-year, $3 million deal over the offseason, is also expected to see a spine specialist after having his last start pushed back due to back stiffness. Wood, 30, previously dealt with back issues in 2019, when he was limited to only seven starts for the Reds.

“We know there are some similar feelings associated with it,” Kapler said. “But I wouldn’t go as far as to say that there’s anything definitively the same about these two instances. What I’d say is that he had a stiff back then, and he has a stiff back now.”

Kapler said Wood is unlikely to pitch for at least the next week or so, making him questionable for Opening Day on April 1. The good news is that the Giants already have another promising starter -- Logan Webb -- ready to step into the rotation if Wood is unavailable for the start of the season. Webb, 24, has emerged as a standout this spring after firing six scoreless innings with 10 strikeouts over his first three Cactus League starts this year.

“I think we have [Kevin] Gausman, [Johnny] Cueto, [Anthony] DeSclafani, [Aaron] Sanchez and Webb as five great rotation options,” Kapler said. “We also have some off days early on. There’s lots of ways to be creative at this point.”

Two other fifth-starter candidates, non-roster invitees Nick Tropeano and Shun Yamaguchi, also worked two innings apiece against the Royals on Monday. Tropeano struck out two and limited Kansas City to two hits, while Yamaguchi gave up a run after Seuly Matias singled and came around to score on a wild pitch in the eighth.

“I thought both of them looked good,” Kapler said. “Tropeano, in particular, had a nice changeup working in his second inning of work. With Yamaguchi, we think his split is a really good weapon. We want to see him use it more, and he did today.”

Núñez was picked up from the Mets in the Rule 5 Draft in December and impressed early in camp, but his velocity noticeably dipped in his last outing against the Rockies on Friday, and he was forced to leave the game early with what was initially described as right wrist pain. An MRI exam then revealed posterior inflammation in his right elbow, leading to the eventual discovery of the UCL sprain.

“What we’ve seen from Núñez is a guy who throws 96-97 mph with his fastball,” Kapler said. “He has a really good slider. Big, strong body. Very confident kid. Works fast. We want to see the best possible outcome here for him, but we’ll cross that bridge when we get there.”

Worth noting

• Left-hander Anthony Banda made his first start of the spring for the Giants on Monday and struggled in the first inning, giving up four runs (two earned) on five hits while managing to record only two outs. Kapler brought in another lefty, reliever Luis Gonzalez, to end the inning, but Banda was permitted to re-enter the game in the second and worked around a pair of hits to cap his outing with a scoreless inning.

• Austin Slater made his first start of the spring in center field on Monday and logged one putout, a fly ball off the bat of Bubba Starling, in the third. Slater has been slowed by hamstring tightness this spring, but he is one of several center-field options the Giants are evaluating as they try to find more depth behind projected starter Mauricio Dubón.

• It was a quiet day for the Giants’ offense, which was kept hitless until Alex Dickerson led off the fifth with a double. San Francisco finally got on the board in the seventh, when Darin Ruf doubled and scored on a groundout by Dubón.

Up next

The Giants will host the Rangers on Tuesday night at Scottsdale Stadium at 7:05 p.m. PT. Veteran right-hander Johnny Cueto will make his third start of the spring and oppose Texas left-hander Taylor Hearn.