Guzman, who has a 3.15 career ERA in 74 relief appearances, will hopefully be able to pitch in a simulated game by mid-March.
"It's a long shot," Cubs manager Mike Quade said. "He's here, he'll work, you know he'll do that, and modern medicine is unbelievable. A quick Tommy John, and you're throwing 94 to 98 [mph]. If he gets involved in this sometime, someday, it'll be great. Right now, it's a long way off."
Cubs pitcher Carlos Silva went home Monday with a 103-degree fever but was on the schedule to throw off the mound on Tuesday.
Others scheduled to throw Tuesday include Braden Looper, Casey Coleman, Trey McNutt, Thomas Diamond, Todd Wellemeyer, Randy Wells, Andrew Cashner, Kerry Wood, Justin Berg, Jay Jackson and Marcos Mateo.
Lefty James Russell had his first side session Monday. He's a candidate for the rotation, but if it doesn't work, Quade said Russell can easily be inserted back in the bullpen.
Pitching coach Mark Riggins has pitchers throwing in groups of four, and is having the sessions filmed for review. Quade stayed away.
"I don't want to be around when these guys are throwing sides right out of the chute," Quade said. "You ask guys to come to camp, take their time, get ready to compete for the games. You're not going to make the club today. [They might think], 'You know what, the skipper's around, he's watching on the side,' and they don't need that. The veteran guys, it probably doesn't affect."