Guerrero wasn't expected to be ready for a promotion to the big leagues until at least the middle of June, but that could change based on the early reports out of Dunedin, Fla.
"I'll tell you this, it has quickly shortened that up based on how he feels," Farrell said of Guerrero, who signed a Minor League contract on May 10. "Just by the way he is taking BP, how he's gone about his work, how he feels physically."
Guerrero wasn't scheduled to start appearing in games at extended spring training until next week, but that timeline has been moved up. The 37-year-old veteran will see his first action against live pitching on Friday and is expected to hit in every inning of the simulated game.
The Dominican native likely will also play four to five innings in the outfield, but the organization still views him primarily as a DH at this point in his career.
"Probably more DH, and I think the fact he's playing the outfield is more just to get his body into overall shape," Farrell said. "Get his legs under him and just get back to baseball activity."
Guerrero's quick progress is coming at the right time. Starting first baseman Adam Lind was optioned to the Minors on Thursday, while DH Edwin Encarnacion has shifted over to first. That could create a spot on the 25-man roster for Guerrero in the near future if he continues a strong showing at the club's Minor League complex.
The 16-year veteran hit .290 with 13 homers and 63 RBIs while posting a career low .733 OPS in 145 games with the Orioles last season.