Right-hander Josh Geer will officially be recalled on Sunday and will start in place of Silva against the Phillies at Citizens Bank Park.
Silva suffered the injury on Monday against the Mets at Citi Field on Monday during an at-bat that saw him earn his first Major League hit.
Silva allowed five runs in 4 2/3 innings, three of which came with two outs in the fifth when David Wright hit a three-run home run.
Padres manager Bud Black said he thinks Silva's stint on the disabled list could surpass 15 days and that the injury is similar to the forearm strain starting pitcher Cha Seung Baek suffered late in Spring Training. Baek is still on the disabled list.
Geer was 1-1 with a 3.60 ERA in two starts with Triple-A Portland. Geer is certainly no stranger to the Padres, having impressed in a trial run last September when he had a 2.67 ERA and a 2-1 record in five starts.
"In talking with [general manager] Kevin [Towers] and our Minor League people ... we thought it was the best thing to do for our club and the integrity of our bullpen," Black said on Saturday.
"[Geer's] arm strength is built up, and he has two starts in Portland. And it fell on his day [to start]. It all made sense."
Geer was consider during Spring Training a candidate to win a job in the starting rotation, but compiled a 10.43 ERA in five Cactus League starts, with opponents hitting .328 against him.
His velocity wasn't what it was in September, which might be a result of the fraying of the ulnar collateral ligament in his right elbow in the final week of the regular season.
Corey Brock is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.