Santana will pitch on Monday for high Class A Rancho Cucamonga, with Lackey following on Tuesday for Triple-A Salt Lake. They're expected to need about three outings each to get ready, which would have them back around May 20, if all goes well.
Less clear is the projected return of Kelvim Escobar, coming back from shoulder surgery. He is being tentatively targeted for June as a starter. But Scioscia left the door open that Escobar, to fill a pressing need, could come back as a reliever, a role he occupied before emerging as a dominant starter.
By reclaiming their rotation slots -- Lackey and Santana initially, and then Escobar -- current starters such as Dustin Moseley (on the 15-day disabled list with right forearm tightness), Shane Loux and Matt Palmer would become available to absorb bullpen duties. Anthony Ortega, younger than the others and in need of experience, would return to Triple-A Salt Lake to be groomed as a starter.
One key middle-relief component, Darren Oliver, is expected back on Monday in Oakland after joining the DL crowd with a strained left triceps.
"We're looking forward to some of those decisions," Scioscia said. "It's going to be a welcomed meeting with our staff when we have those decisions ... where you have an abundance of guys for one role.
"That's the depth we're going to need on the pitching side. We're not quite there. The process of getting Santana and Lackey will keep moving forward, and that will definitely have a positive spillover effect on our bullpen."
Rafael Rodriguez, Jose Arredondo and Brian Fuentes let a 9-4 lead get away in the final two innings on Friday night, the Yankees scoring four times in the eighth and twice in the ninth to stagger the Angels, 10-9.
Moseley has flourished in the past in relief, and Loux and Palmer have the experience and stuff to also be effective in those roles if they surface.
The Angels are carrying seven relievers, including one, Fernando Rodriguez, who has not yet made it to the mound for his Major League debut.
Scioscia said he wants all hands on deck to keep arms relatively fresh in case a starter is knocked out early.
Oliver's return to full health seemingly would eliminate the need for the seventh reliever. The durable lefty worked 72 innings last season and is capable of pitching multiple innings to bridge the gap to the back end of the bullpen.