OAKLAND -- The Giants were relieved to learn Tuesday that Johnny Cueto has a mild flexor strain and nothing more serious.
The right-hander exited after three innings during his rehab start at Class A Advanced San Jose on Monday with what the Giants described as forearm tightness. But an MRI revealed Cueto's injury isn't season-ending.
The team plans to rest him for a week while also putting him through his normal exercise and conditioning regimen. He was originally placed on the disabled list with blisters on his throwing hand.
"You always have a little concern when someone feels something there in the forearm," Giants manager Bruce Bochy said. "Talking to Johnny, it seems like he's in a good frame of mind. Sure, he's disappointed in what's happened here. He needs a little bit of time."
Head athletic trainer Dave Groeschner said he's optimistic Cueto will pitch again in 2017.
Cueto's setback came roughly five days before he was scheduled to rejoin the Giants' rotation.
"This is a pretty good prognosis overall," Groeschner said. "He's relieved a little bit. We've got a plan to give him some rest. ... [After a week], we'll figure out where he is and put together a pitching program for him."
Cueto's injury comes a few months before he must make a decision about his future in San Francisco. The 31-year-old could opt out of the remaining four years of the six-year, $130 million contract he signed before the 2016 season to become a free agent.
For his part, Bochy said Cueto and ace Madison Bumgarner would complement each other well in 2018.
"Obviously we think a lot of Johnny. ... Our hope is to have those two healthy back going 1-2 next year," Bochy said. "They're so important to our success. We still feel very strongly about that."
Parker's return could prompt change
Giants outfielder Jarrett Parker, who has missed most of the season with a fractured right clavicle, could return from his Minor League injury rehabilitation stint as soon as Wednesday.
Bochy indicated Parker's arrival could stir some debate. In the 28-year-old's absence, Gorkys Hernandez, Denard Span and Hunter Pence have established themselves as San Francisco's starting outfield, from left to right. However, Parker has power potential and was the team's Opening Day left fielder.

Bochy said he plans to "huddle up" Wednesday with his coaching staff and general manager Bobby Evans to discuss how Giants outfielders will be used through the remainder of the season -- "the number of games they play every week from this point on," Bochy said. "It might not be every day."
Popular clubhouse assistant dies
David Lowenstein, a clubhouse assistant whose service dates back to the 1980s, died Tuesday morning after a lengthy illness, the Giants said. Lowenstein was 60.
Lowenstein was former general manager Al Rosen's stepson, but that didn't stop players from making him the butt of jokes or the victim of pranks. Moreover, Lowenstein endeared himself to players with his friendly nature.
"It's a sad day," Bochy said. "Everybody who had a chance to spend time around David had fun with him. He's one of the funniest guys I've been around."