Santana was out of the majors last season while recuperating from surgery on his left shoulder. He signed a one-year, incentive-laden contract with the Orioles on Tuesday, and he worked out with them for the first time Wednesday.
The 34-year-old Santana said he's not yet ready to pitch in the major leagues. Baltimore has set a target of June 1 for his arrival.
Santana, once a dominant pitcher for the Minnesota Twins and New York Mets, is eager to show he can still be effective. Last week in a showcase for the Orioles and other major league teams, Santana struggled to throw more than 80 mph.
"As long as I don't feel anything in my arm, I'll be able to go out there," he said. "I know what to do. And again, you've got to make adjustments. There's no question about it. That's what I'm going to do. But right now, I don't really know what my velocity will be."
Santana was a two-time Cy Young Award winner with Minnesota. He pitched the only no-hitter in the history of the Mets in 2012.
He said he's comfortable that no one will try to rush his comeback.
"One of the biggest things is they understand exactly where I am as far as my rehab and everything. And then they've got the confidence that they'll be able to help me to come back. We're on the same page and I'm very happy for that," Santana said.
"I'm excited. I think it's great," Showalter said. "I'm not going to say it's a no-lose proposition. There are things you lose, but it makes a risk worth taking. I think it's exciting, the possibility down the road. I'm hoping we get five starters who pitch so well, we don't need it."
Showalter looks at Santana as a starter but said he could pitch out of the bullpen if needed. Santana hasn't made a relief appearance since 2003. More important is Baltimore's ability to be a factor in the AL East.
"This team is going to contend," Santana said. "And I am going to prepare to try to help as much as I can in any way. So whenever it is time for me to join the team I'm going to help as much as I can and hopefully it will be sometime soon."