4 Possible Return Scenarios For Diamondbacks' Merrill Kelly

The Arizona Diamondbacks are dealing with more than their fair share of early injuries already this spring. In addition to missing several key players due to holdover injuries from last year, Corbin Carroll and Merrill Kelly are both dealing with injuries that have put the start of the season in doubt for them.

Kelly is dealing with intercostal nerve irritation, an injury that has already caused him to shut down from a live BP session and knocked him off track to make the opening day start in Los Angeles.

It's not entirely clear when Kelly will throw off a mound again, but after speaking with Torey Lovullo and investigating the situation further, we can present a number of possible scenarios

Best Case Scenario: Kelly Pitches Game 5 of the Season

The season starts on March 26, and there is an off day between the Dodgers series and the first home series against the Detroit Tigers. Torey Lovullo was asked if they had a date in mind for when Kelly would need to throw off a mound to begin his progression towards taking a turn in the rotation, albeit not game one.

"We feel like, given the progress he's made, and the evaluation that was done by a lot of really good people, that if we do start the progression sooner than later, he might be on the back end of our rotation. That's what we're going to hold out hope for, but anything's possible, we've still got to wait until it's all said and done," Lovullo said.

Based on what Lovullo is saying, it would appear that Kelly will need to be able to throw off a mound by the end of the upcoming weekend, or next Monday, March 2 to be ready to pitch March 31 against the Tigers, which would be the fifth game of the year.

Scenario 2: Go With 4-Man Rotation First Time Through

Due to the off day on March 29, the D-backs also have the option to use four starters the first time through. That means keeping the first four starters on four days' rest, and whoever gets the ball on opening day will then pitch March 31 versus the Tigers.

That would allow the D-backs to push Kelly back to April 4 against the Atlanta Braves, or game nine of the season. This is less than ideal for two reasons, however.

The team would prefer not to push the other four starters that hard, and also they could probably use the extra reliever during those first nine games in case there are any short outings.

Scenario 3: Place Kelly on the 15-day Injured List Backdated to March 23

A third option is to have Kelly begin the year on the 15-day injured list. MLB rules allow teams to backdate that to three days before the start of the season, or March 23.

Should the team take that route, the earliest Kelly could return to the rotation would be April 7 against the New York Mets in Citi Field.

This option would allow the team not to rush Kelly while also staying covered in the bullpen. Ultimately Kelly would have only missed two starts.

Scenario 4: Kelly Does Not Progress, Misses Significant Time

None of the first three scenarios above are a bad outcome, as Kelly would miss only one or two starts at most. However, as Lovullo said, anything is possible.

Kelly was signed to a two-year, $40 million contract with a vesting option for a third season. Now 37 years old, it's somewhat discouraging that he's begun the year with what has the potential to be a long-term nagging injury.

The range of outcomes and return time for intercostal nerve irritation is quite wide, according to online resources, anywhere from 2-3 weeks to several months.

Arizona Diamondbacks On SI will continue to monitor Kelly's progress and report the latest updates as they happen.