Kelley left Tuesday's game with a strained forearm and could miss the rest of the season, MLB.com's Bill Center reports.

EDGE Analysis

He is set to get an MRI Wednesday, but the injury, which forced Kelley to leave the mound after throwing a warm-up pitch, is believed to be quite serious. Jon Edwards was called up from Triple-A to help bolster the Padres' bullpen down the stretch.

Kelley left Tuesday's game with an injury before even throwing a live pitch, the Union-Tribune's Dennis Lin reports.

EDGE Analysis

He went out to warm up in the seventh inning and then hurt himself on a warm-up pitch and immediately walked off the field. These are often the scariest pitcher injuries, as it often means something is really wrong. More information should be available Wednesday.

Kelley (calf) was reinstated from the 15-day disabled list Friday. Kelley will reclaim a spot at the back of the San Diego bullpen, sending Nick Vincent back to Triple-A El Paso.

Kelley (calf) has rejoined the team and is likely to be activated Friday. After pitching two scoreless innings for Triple-A El Paso in a rehab assignment on Monday, Kelley will be activated off the disabled list. Kelley has appeared in six games and pitched 5.1 innings for the Padres this season, posting an ERA of 10.13 and earning two losses in that time.

Kelley (calf) worked two scoreless innings at Triple-A El Paso on Monday and is slated to pitch again Wednesday, Dennis Lin of the Union-Tribune reports. Kelley struck out two batters and surrendered one walk over his two innings of work Monday. Barring a setback in his next outing, Kelley will be eligible to be activated off the disabled list Thursday.

Kelley will make rehab appearances with Triple-A El Paso UT San Diego reports. Kelley went to the disabled list with a strained left calf and made one appearance with High-A Lake Elsinore in which he pitched one scoreless inning. He struck out two batters and walked one. Kelley is expected to pitch both Monday and Wednesday with Triple-A El Paso. He is eligible to be called up as early as Thursday for the Padres' series with the Diamondbacks.

Kelley (calf) will begin a rehab assignment Friday with High-A Lake Elsinore, Jeff Sanders of the San Diego Union-Tribune reports. Kelley threw a 25-pitch bullpen session Wednesday without incident and reported he was ready to begin a rehab stint shortly afterward. He'll likely need to appear in a few rehab games, but a return as soon as he's eligible to come off the disabled list on May 7 seems to be within reach.

Kelley (calf) threw off a mound to live hitters Monday, Corey Brock of MLB.com reports. Kelley was placed on the 15-day DL with a left calf injury Friday, so it's an encouraging sign that he's already been able to resume throwing.

Kelley was placed on the 15-day DL on Friday with a left calf injury, Padres announcer Bob Scanlan reports. He had been pretty brutal in the early going, posting a 10.13 ERA in 5.1 innings. Kevin Quackenbush was recalled to replace him in the Padres' bullpen.

Kelley gave up three earned runs and walked two batters in just 0.2 innings of relief work Sunday against the Diamondbacks. Kelley has made three appearances so far this season, allowing opponents to get on base 50 percent of the time and allowing a slugging percentage of .929.