DENVER -- As the D-backs prepared for their series opener against the Rockies at Coors Field on Monday afternoon, right-hander Luke Weaver was placed on the 10-day injured list and traveled to Phoenix to have an MRI on his right forearm. The results showed a right forearm strain, and manager Torey Lovullo said the club is seeking a second opinion.

In a corresponding roster move, Arizona recalled right-hander Jimmie Sherfy from Triple-A Reno.

Weaver exited Sunday's series finale in San Francisco in the sixth inning due to tightness in his right forearm after giving up one run over the first five frames. Buster Posey opened the sixth for the Giants with a single, and after the pitch, Weaver was seen opening and closing his pitching hand in discomfort.

The 25-year-old Weaver was one of the players the D-backs received from the Cardinals in the Paul Goldschmidt trade. He has been one of Arizona's best starters this season, posting a 3.03 ERA over 11 starts with 68 strikeouts and 14 walks.

After Taijuan Walker needed Tommy John surgery last year, despite looking strong to Lovullo after the right-hander experienced forearm tightness, the D-backs' manager is being more cautious in his thought process with Weaver.

"I had that conversation today," Lovullo said. "I was totally shocked when Taijuan's MRI came back the way it did, because he was showing strength, he was very upbeat, just having some muscle fatigue and tightness all pitchers go through. That's what I really believed, until the moment I got those results. There's just so much unpredictability with a pitcher's arm, shoulder, elbow.

"I'm going to remain optimistic. I live in the clouds with the rainbows and where the butterflies fly every day, but I'm going to be a little more open-minded with what I saw with Taijuan last year."

With a new vacancy in the starting rotation, Lovullo said right-hander Taylor Clarke, who has been impressive in two starts this year, will stay in the rotation and start Thursday afternoon against the Rockies. Friday's starter remains to be decided.

Clarke, 26, has given up five runs over 12 1/3 innings (3.65 ERA) as a starter against the Rays and Giants, though opponents hit .283 against him in those outings.

As Lovullo weighs who will start Friday, and perhaps fill Weaver's slot beyond that, he said "it wouldn't be so bothersome" to place three rookies in the rotation because of "extenuating circumstances." Another candidate for the rotation may be 24-year-old right-hander Jon Duplantier, who owns a 2.25 ERA in five relief appearances this season. Merrill Kelly is already in the D-backs' rotation.

Zack Godley, who began the season in the starting rotation, struggled to a 7.71 ERA in eight starts (he's made four relief appearances as well) and was moved back to the bullpen following his last start May 18 vs. the Giants. He allowed four runs over 3 1/3 innings in that outing.

Lamb resumes baseball activity

Jake Lamb, recovering from a left quad strain, has resumed baseball activities after being shut down for a few days due to having what Lovullo called "a neutral day" Wednesday. Lovullo added that it wasn't a step backward, but Lamb felt some weakness in the quad and was shut down for precautionary reasons.

"He got back on the field [beginning Friday], hit, ran, threw, took some ground balls," Lovullo said. "He's in a better place than he was, like I said, when he was in that neutral day or two. So, he's progressing."

Though Arizona scored 34 runs during the three-game series in San Francisco, the club could use Lamb's left-handed bat in the lineup as soon as possible, given the D-backs' .661 OPS vs. right-handed pitching from May 6-23 and overall offensive slump prior to the series against the Giants.