Simpson will undergo surgery Tuesday to repair the ulnar nerve in his left elbow, Christina De Nicola of MLB.com reports.

EDGE Analysis

It's expected to be around three months before Simpson will be ready to pitch in games again, so this will put him out at least until after the All-Star break. The southpaw initially suffered the injury during spring training and made an unsuccessful attempt at resting and rehabbing the injury before eventually opting for surgery.

The Marlins transferred Simpson (elbow) to the 60-day injured list Saturday.

EDGE Analysis

Simpson started the season on the 15-day IL with left elbow ulnar neuritis. He made an appearance with Single-A Jupiter on April 6 and appeared close to returning to the Marlins' bullpen, but the left-hander hasn't pitched since that outing. Right-hander Kyle Tyler was selected from Triple-A Jacksonville in a corresponding move, and Tyler will fill in for Simpson in Miami's bullpen.

Simpson (elbow) is expected to throw a bullpen session later this week, MLB.com reports.

EDGE Analysis

Simpson opened the season on the 15-day injured list while recovering from left elbow neuritis, but he appeared in line for close to a minimum-length stay on the shelf after he was able to begin a rehab assignment with Single-A Jupiter on April 6. However, he experienced a setback during that one-inning outing and hasn't pitched since. The setback doesn't appear to be a major one given that Simpson should get back on the mound soon, but he still may be around a week away from restarting his rehab assignment.

Simpson (elbow) will begin a rehab assignment with Single-A Jupiter on Saturday, Jordan McPherson of the Miami Herald reports.

EDGE Analysis

The left-handed reliever has been working his way back from an elbow issue and is finally ready to test himself in a game setting. Simpson missed all of spring training, so he'll likely require a handful of rehab appearances before becoming an option for the Marlins bullpen.

Simpson (elbow) will throw a bullpen session Saturday, Jordan McPherson of the Miami Herald reports.

EDGE Analysis

Simpson has dealt with a left elbow issue since late February and began the season on the injured list. He looks to be making nice progress, though, and could be ready for a rehab assignment soon.

The Marlins placed Simpson on the 15-day injured list Thursday with left elbow ulnar neuritis.

EDGE Analysis

Simpson seemed likely to begin the season with a middle-relief role in the bullpen for Miami, but he dealt with elbow discomfort during spring training and will open the season on the IL. According to MLB.com, Simpson was able to throw last week while hitters stood in the batter's box, so it may not be long before he's ready to head out on a minor-league rehab assignment.

Manager Skip Schumaker said Sunday that Simpson is dealing with left elbow discomfort that's similar to nerve irritation, Christina De Nicola of MLB.com reports.

EDGE Analysis

Simpson hasn't pitched since Feb. 27, and Schumaker said the club is being cautious since the left-hander "still feels it a little bit." Given the length of the layoff, the 26-year-old will likely need to ramp things up soon to have a chance of being ready by Opening Day.

Simpson was optioned to Triple-A Jacksonville on Sunday, Jordan McPherson of the Miami Heraldreports.

EDGE Analysis

The left-hander was called up by Miami on Tuesday but didn't make his MLB debut during his time with the team. Simpson will return to Jacksonville, where he has a 4.50 ERA over 32 innings this year.

Simpson was recalled Tuesday from Triple-A Jacksonville, Jordan McPherson of the Miami Herald reports.

EDGE Analysis

Simpson has struck out 62 batters in 36.1 innings this season in the minors, but all of those whiffs have come alongside a 4.71 ERA and 1.54 WHIP. The 26-year-old left-hander will be making his major-league debut whenever he gets into a game for the Marlins.

Simpson (shoulder) struck out two and allowed no hits and one walk over one inning in his lone appearance since being reinstated from Triple-A Jacksonville's 7-day injured list Saturday.

EDGE Analysis

Simpson was on the IL for nearly three months due to a left shoulder injury. The 25-year-old reliever has yet to make his MLB debut, but he occupies a spot on the Marlins' 40-man roster and could be in the mix for a late-season call-up.