PHOENIX -- The Arizona Diamondbacks continued to deal with a surge of early-season injuries, putting starting pitcher Zac Gallen and first baseman Christian Walker on the 10-day injured list Wednesday.
Gallen has a sprained right ulnar collateral ligament, which is the ligament replaced in Tommy John surgery. Walker has a sore right oblique; a similar injury put him on the IL earlier this season.
Gallen has emerged as one of baseball's top young pitchers. He finished ninth in the NL Cy Young Award voting last season and had a 3.04 ERA through five starts this year.
Manager Torey Lovullo was confident the D-backs' medical team caught Gallen's injury early, saying the elbow sprain was ``minor'' and that he was hopeful the 25-year-old would be able to avoid having the Tommy John procedure.
"We have multiple opinions that are coming in and as of right now, it looks like we're going to reassess in a couple weeks," Lovullo said.
Gallen missed his first start of the season with a hairline fracture in his right forearm that happened when he was taking batting practice during spring training. Lovullo said the two injuries aren't related.
Walker has already missed three weeks this season because of oblique soreness. The 30-year-old returned on May 4 and played in seven games before getting hurt again on Monday. Lovullo said Walker's injury is in the same general area.
"These are challenging times," Lovullo said. "It's stuff we talk about, stuff we budget for and what I'll say is every team walks through very challenging situations. It's how we respond to those situations that's going to separate us."
Gallen and Walker join a host of other D-backs who have made trips to the injured list this season. Outfielders Ketel Marte, Kole Calhoun and Tim Locastro, shortstop Nick Ahmed and pitchers Joakim Soria, Tyler Clippard and Taylor Widener have all missed time with injuries.
The Diamondbacks called up pitcher Seth Frankoff and utility player Andy Young to take the place of Gallen and Walker on the active roster.
The Associated Press contributed to this report.