Out for the past six weeks after suffering a concussion, Gutierrez was supposed to start a rehab assignment with Class A Everett on Sunday, but that was delayed when the outfielder experienced a recurrence of headaches.
Gutierrez saw the doctor again and manager Eric Wedge said they are changing some medications, which will hopefully yield better results.
"[We] feel like that's going to help him," Wedge said "He's going to be exercising today, back to baseball activity [Tuesday] and keep progressing from there."
Gutierrez has appeared in only 12 games this season, as he's dealt with a partially torn pectoral muscle and plantar fasciitis, along with the concussion he suffered June 28 against the Red Sox.
"Nobody's more frustrated than Gut, I think everybody understands that," Wedge said. "All the emotional roller coaster he's been on. Obviously it's a big loss for us. Defensively it's a big loss for us. Offensively, a veteran right-handed bat we could really use. Obviously what he means for us in the outfield and the way we're able to spread other people around, has a big impact on us too."