Alvarez (shoulder) will throw a 40-pitch bullpen session Saturday, John Hickey of the San Jose Mercury News reports.
For the first time this spring, Alvarez will mix breaking pitches into his arsenal when he's on the bump for a bullpen session. He's still a ways away from being ready for game action, but he has increased his pitch count during his bullpens and is gradually working on mixing in all of his pitches. If Alvarez's bullpen Saturday goes without a hitch, he should remain on track for a return some time in May.