© 2014 MLB Advanced Media, L.P. All rights reserved.

7/1/2014 12:42 A.M. ET

Cespedes day to day with hamstring injury

DETROIT -- A's left fielder Yoenis Cespedes prematurely exited Monday's 5-4 loss in Detroit with a left hamstring injury.

It won't be clear until Tuesday whether it's just a cramp or a strain. Regardless, there's a "good chance he doesn't play" on Tuesday, manager Bob Melvin said.

The A's are unaccustomed to the humid weather they've experienced on this eight-game, 10-day road swing through New York, Miami and Detroit. Even starter Scott Kazmir was hampered by a left calf cramp Monday, forcing him out of the game with one out in the sixth.

"It was tough, it really was," said Kazmir. "It was tough to just stop the sweating. The entire game, it was nonstop. Those guys were going through it too, though. Just seems this entire road trip, that's the way it's been. It's going to be muggy, it's going to be hot. I think we're getting acclimated, but it's a lot different to the air we have in California."

Prior to departing, Cespedes singled and scored a run in the sixth to extend his hitting streak to a career-high 14 games.

Reddick to rest for week after MRI comes back clean

DETROIT -- Though A's outfielder Josh Reddick was concerned about his latest right knee injury being more serious than the last, an MRI has revealed otherwise.

"Nothing in there any worse than before, structurally," manager Bob Melvin said Monday in Detroit.

Reddick, who exited Saturday's game in Miami after aggravating the knee, returned to the Bay Area the next evening to go over his MRI with team doctors. Now he can breathe a sigh of relief and embark on a similar rehab process as he did at the start of the month. That one lasted three weeks.

"It is a relief," said Melvin, "because after a second time and him having to pull himself out of the game, it was, at the time, a bit worrisome. And I'm glad we got better news."

On doctor's orders, Reddick will rest for about a week before resuming any baseball activities. The A's have plenty of options in right field in the meantime. Brandon Moss made the start there Monday in the opener vs. the Tigers at Comerica Park, while a banged-up Stephen Vogt manned first base. He, too, of course can play the position, and Craig Gentry gives them a third alternative.

Norris seeing improvement in sore back

DETROIT -- Lingering back soreness sidelined Derek Norris for a third straight game Monday, but A's manager Bob Melvin is hopeful the catcher will be back behind the plate by the time this three-game set in Detroit concludes on Wednesday.

Norris initially departed Friday's game in Miami with pain in his lower back, similar to what he experienced earlier this season. The day after, he could hardly walk. Now he can touch his toes and twist side to side pain-free -- all signs of improvement.

But Norris isn't quite up to par with baseball activities just yet.

"Backs just take time," Norris said. "There's no quick fix, nothing you can really do to take the time to let the muscles that were [ticked] off cool down.

"Today I took some swings [at] about 60 or 70 percent, and everything felt OK. Not great, not bad. Overall, I just felt OK. I'll stretch and throw and start knocking off the rust, and if my body responds positively from today, then we'll go from there."

O'Flaherty's rehab assignment in final stages

DETROIT -- Lefty Eric O'Flaherty's rehab assignment is nearing its end, and it seems the A's could welcome back the Tommy John patient as soon as this week.

O'Flaherty will make his ninth rehab appearance, and eighth with Triple-A Sacramento, on Tuesday, when he's expected to enter in the middle of an inning -- as opposed to starting one, just as all relievers are often called on to do.

That could be O'Flaherty's final hurdle.

"The only thing we haven't covered with him is back-to-back days," said manager Bob Melvin, "and that's something I'm not sure we have to do."

Asked specifically if O'Flaherty could join the team on the next homestand that begins Thursday, Melvin grinned and offered, "Chance for anything."

When the reliever does make it back, it will mark his first time on a big league mound since May 17 of last year with the Braves. The A's risked a two-year, $7 million deal on O'Flaherty in the offseason, hoping to get back the same arm that posted a 1.99 ERA in 295 appearances with Atlanta over the previous five seasons -- including a 1.45 mark over his last three.

O'Flaherty's presence would only add to an already envied group of A's relievers, whose 2.87 ERA ranks second in the American League. It also sets up an intriguing roster decision, since most of their relief arms are locks to stay. Jim Johnson and Jeff Francis are seemingly the two on the chopping block.

Worth noting

• The A's on Monday agreed to terms with five of their selections from the 2014 First-Year Player Draft: right-hander Brett Graves (third round, Missouri), right-hander Heath Fillmyer (fifth, Mercer County CC), shortstop Branden Cogswell (seventh, Virginia), right-hander Tyler Willman (12th, Western Illinois) and second baseman Trent Gilbert (15th, Arizona).

MLB.com has learned Graves signed for $510,000, just under the slot value of $519,200. Fillmyer received a $305,000 bonus, which is $16,700 above pick value.

Jane Lee is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.