Detroit Tigers relief pitcher Sergio Arellano is going to be unavailable for the next couple of weeks. The reliever suffered back stiffness while pitching and is currently listed as day-to-day, though the official timeline points to a more defined absence.

It is the kind of nagging ailment that pops up without warning and refuses to leave quietly. Arellano felt the tightness during his outing on the mound. The training staff evaluated him and handed down the diagnosis of back stiffness. They are officially calling it a day-to-day injury, which is standard clubhouse terminology until a guy actually picks up a baseball and throws it without wincing. Realistically, the club expects the stiffness to keep him out of action for about two weeks.

Pitching puts unnatural torque on the human body, and the back usually ends up paying the toll when something goes wrong. A two-week absence is not a season-ender, but it does thin out the bullpen and force the skipper to get creative. The coaching staff will have to mix and match with the remaining arms to cover the late innings Arellano would normally handle. You just plug in the next guy and hope the bridge holds.

For now, Arellano’s daily routine shifts from the bullpen mound to the training room. His job is to rest, get treatment, and wait for the stiffness to finally fade. The Tigers will manage the bullpen workload in the meantime, keeping their reliever on the shelf until he can prove he can twist and fire without issue. There is no sense in rushing a back issue, because rushing it usually just means you end up right back where you started.

Notebook

• [I]Injured (dehydration),day-to-day for 1 day.