Diamondbacks face another obstacle, Giants (Apr 18, 2018)

PHOENIX -- The Diamondbacks' fast start has come with obstacles, and they ran into another one this week.

Already without bats Steven Souza Jr. and Jake Lamb, Arizona learned Tuesday that right-hander Taijuan Walker has an ulnar collateral ligament injury.

Diamondbacks manager Torey Lovullo did not get into specifics about the injury, which is often a precursor to Tommy John surgery. But the fact that Walker is seeking a second opinion means a UCL tear is feared.

"You guys can probably figure that out on your own," Lovullo said. "Taijuan is getting a second opinion to see the type of injury. Every bit of information we have now is vague. Where it takes him from here, we're not sure."

Walker was removed from his start in Los Angeles on Saturday after one inning because of forearm tightness. He was initially diagnosed by the D-backs' medical team and is to get a second opinion in New York on Wednesday, Lovullo said.

As far as pitching injuries, no team can relate as well as San Francisco, which resumes its three-game series against the Diamondbacks on Wednesday.

Right-hander Johnny Cueto returned to the mound after missing two starts while on the disabled list, and struck out 11 in seven scoreless innings in Tuesday's 1-0 loss to Arizona. But he is the only one of the Giants' top three starters to have pitched this season.

Nos. 1 and 3 starters Madison Bumgarner and Jeff Samardzija have missed the first three weeks, and Bumgarner is expected to miss another month with a fractured hand. Samardzija threw a bullpen Tuesday and is on track to make his first start of the season this weekend.

"It's always good to get a guy back and have another one who is really close," said San Francisco manager Bruce Bochy, whose team has lost four in a row after losing the final three games in San Diego over the weekend.

"Get more to who we are and get this rotation back. This past weekend it caught up with us a little bit, but I think overall we've done all right."

Matt Koch and Braden Shipley seem to be the likely candidates to take Walker's next turn through the rotation Friday. Koch broke camp with the team as a long reliever but was returned to Triple-A Reno last week. Right-hander Shelby Miller underwent Tommy John surgery early last season and is not scheduled to return to the mound until June.

Arizona left-hander Robbie Ray will face Giants right-hander Chris Stratton on Wednesday.

Ray is 2-0 with a 5.74 ERA and has been somewhat inconsistent in his first three starts. He has 23 strikeouts in 15 2/3 innings but he also has walked 11 and given up four home runs. Buster Posey hit a game-tying three-run homer off Ray in the fifth inning April 11, after which Ray was removed. The Diamondbacks rallied for a 7-3 victory.

"He's been throwing the ball OK," Lovullo said. "I know by Robbie's standards, he would be the first to say that he hasn't been as successful as he was last year. But I know that he is working as hard as he possibly can to make that happen as quickly as he possibly can."

Ray was 15-5 last season and had great success against the Giants, going 3-0 with a 1.48 ERA in four starts while striking out 29 in 24 1/3 innings. He is 4-1 with a 2.82 ERA against the Giants in his career, with three of those victories coming at AT&T Park.

Stratton is coming off his best career outing, a 7-0 victory at San Diego in which he gave up only one hit -- a single -- in seven innings. He struck out four and walked three in his longest career outing.

"He's a four-pitch guy that throws strikes, command of the strike zone, a good mix of pitches and doesn't beat himself," Bochy said. "Did a great job last year and he's continued that. He's matured as an overall pitcher. You look at the body of work he gave us last year and he's shown that wasn't a fluke."

Stratton was 1-1 with a 3.18 ERA in three starts against Arizona last season, striking out 18 and walking 10 in 17 innings. He had not faced the Diamondbacks in his two previous seasons in the majors.