The Blue Jays never expected Santana would be ready for Opening Day and have put an emphasis on taking a cautious approach in his attempt to make it back to the big leagues. Santana hasn't appeared in the big leagues since 2012 because of a wide variety of injuries.
"I'm guessing, from what I heard, don't hold me to it, but they're hoping by the middle of April," Blue Jays manager John Gibbons said when asked about the start of Santana's throwing program off a mound.
Santana isn't currently injured, but multiple surgeries on his shoulder have taken a toll over the years. His comeback attempt began in the Venezuelan Winter League but was cut short when a previously repaired Achilles' tendon became an issue.
Even when Santana does eventually increase his baseball activities, it's not immediately clear how he would fit into the Blue Jays' system. Toronto will start the year with a rotation that includes Drew Hutchison, R.A. Dickey, Daniel Norris, Mark Buehrle and Aaron Sanchez.
Santana likely becomes an insurance policy, but he also has an opt-out clause in his contract for the end of April. The 36-year-old doesn't have a guaranteed contract, but he could earn upwards of $6.7 million on his deal based on a series of incentives, which center around time spent on the active roster and the number of starts made this season.
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.