The 36-year-old Downs, who dodged a stint on the disabled list when an MRI exam revealed no structural or ligament damage, may be back by early next week.
"We're looking good," Downs said. "We're gaining progress. I don't think there's a timetable, but every day it's getting better, so hopefully that just makes it a day sooner."
Downs, who spent two stints on the DL last year, suffered the injury while covering first base and getting spiked by Twins center fielder Denard Span on Thursday. Without him, an Angels bullpen that already had some depth issues is even thinner, as more is being asked of the 39-year-old arms of LaTroy Hawkins and Jason Isringhausen.
Downs knows this -- which is why he has to fight himself not to push his rehab too hard.
"As just an athlete in general, your instincts start to take over and your adrenaline starts to kick in," Downs said. "We're not here to sit and watch; we're here to pitch. We're here to play and do what we can to stay on the field."
Right-hander Bobby Cassevah, who began the year on the DL with right shoulder inflammation, has pitched well during a rehab assignment in Class A Advanced Inland Empire, hurling three scoreless one-inning outings while giving up one hit and two walks.
Cassevah is eligible to be activated, but manager Mike Scioscia said he's still "trying to work his way into his stuff" and needs more time.
"I think he needs a little bit more work," Scioscia said. "I don't think it's a lot, but he needs a little bit more work."