Tests showed the ulnar collateral ligament in Baek's right elbow is fine, but manager Bud Black said Baek won't be picking up a baseball to throw it for some time.
Baek, who was hoping to rejoin the Padres this week after finishing a Minor League rehab assignment, injured his elbow pitching for Triple-A Portland on Saturday. Tests performed Monday showed no ligament damage, but confirmed the original diagnosis of a forearm strain.
"In the immediate short-term, he's just on therapy and he won't be playing catch," Black said. "There's no timetable on when he picks up a ball again and resumes throwing. We'll continue with the rehab in San Diego."
Black said the injury is similar to the one that landed Baek on the disabled list in Spring Training, but stressed it is new.
"My initial thought was that maybe he reinjured the existing injury," Black said. "This is the same thing but in a different part of the forearm. The forearm is comprised of these flexor muscles; he hurt just another spot of that."
It could have been worse for Baek, who had been penciled in as the team's No. 3 starter.
"The ulnar collateral ligament, the 'Tommy John' ligament, checked out fine," Black said.
Black also said right-hander Walter Silva did well at his most recent rehab outing. Silva also has a strained right forearm. Black would not say when Silva would return to the Padres.
"We'll more than likely have Walter make some starts down in Portland, and then we'll evaluate where we are as a pitching staff," Black said.
David Brown is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.