Casilla has been sidelined for much of the past week due to shoulder tightness, Susan Slusser of the San Francisco Chronicle reports.

EDGE Analysis

This explains why Casilla hasn't appeared in a Cactus League contest since March 9. The good news is he appears to be on the mend, as the veteran right-hander is scheduled to throw a bullpen Monday. That said, it's still unclear if the injury will jeopardize his status for Opening Day. Casilla is expected to work in a setup role in 2018, though his fantasy value remains limited given his declining strikeout rate and light workload for a reliever.

Casilla fired a perfect sixth inning in Monday's 6-5 Cactus League loss to the Giants, recording a strikeout.

EDGE Analysis

It was the second consecutive scoreless effort for the veteran reliever, who'd gotten his spring off to a shaky start by allowing seven earned runs over 2.2 innings across his first three appearances. Casilla was a mixed bag in his age-36 season in 2017, the first of his second Oakland tenure. He converted 16 of 23 save opportunities before eventually being displaced from the closer's role, finishing with his highest ERA (4.27) and WHIP (1.36) since 2009, the final season of his first A's stint. Casilla projects to fill the same type of setup role he finished last season in during the 2018 campaign, which should afford him a fair amount of hold opportunities.

Casilla allowed an earned run on a hit over one inning in Monday's 8-3 win over the Tigers. He struck out two.

EDGE Analysis

The former closer allowed a seventh-inning homer to Ian Kinsler but was otherwise sharp, throwing 10 of his 13 pitches for strikes. Casilla's season-long instability has continued in September, as he's given up an earned run apiece in each of his last three outings and in four September appearances overall. He appears relegated to set-up duty at best for the balance of the regular season, especially given Blake Treinen's relative success in the ninth-inning role.

Casilla fired a scoreless eighth inning in Monday's 3-1 loss to the Angels, recording two strikeouts.

EDGE Analysis

Casilla doesn't turn in too many completely clean outings these days, but Monday's did serve as his third of August. Nevertheless, the 37-year-old's current role seems to be much closer to set-up man than closer, and given the extent of his inconsistency since the beginning of July (2-for-6 in save opportunities), it may remain that way for the balance of the campaign.

Casilla fired a scoreless seventh inning in Monday's 7-3 loss to the Orioles, allowing a hit and recording two strikeouts.

EDGE Analysis

The success of Blake Treinen and Casilla's own struggles have likely displaced the veteran reliever from the closer's role for the time being. Monday was Casilla's first appearance since his latest late-inning meltdown, one in which he surrendered three earned runs over just one-third of an inning against the Royals last Tuesday. The 37-year-old has blown seven saves on the season overall, so he may find himself in a similar role to Monday's moving forward.

Casilla came on in the eighth inning Tuesday and suffered his seventh blown save of the season, surrendering three runs on two hits and a walk while recording just one out against the Royals.

EDGE Analysis

Alex Gordon led off the inning with a walk, then Drew Butera hit a two-run shot. Whit Merrifield then flied out and Lorenzo Cain singled and that was the end of Casilla's night. Blake Treinen came on and gave up home runs to Eric Hosmer and Mike Moustakas, but thanks to a huge Oakland rally in the bottom of the eighth inning, Treinen actually got the win after going back out for the ninth inning. This was the first time Casilla had given up a run since July 26, but the meltdown was likely enough to keep him firmly in the eighth-inning role going forward.

Casilla fired a scoreless ninth inning in Sunday's 9-3 win over the Orioles, allowing a hit and recording two strikeouts.

EDGE Analysis

Casilla hasn't notched a save since July 23, but he has compiled two holds and a win over six August appearances. The 37-year-old hasn't surrendered a run since falling apart in a blown save opportunity against the Blue Jays on July 26, making it one of his most effective stretches of the season. Although Casilla has worked his ERA back down to 3.89, it remains to be seen if he'll return to a full-time closer role.

Casilla notched his third hold in Sunday's 11-10 win over the Angels, allowing a hit and issuing a walk over a scoreless eighth inning. He also recorded two strikeouts.

EDGE Analysis

It took Casilla a whopping 32 pitches to get through his one frame, getting only 17 of those offerings into the strike zone. The veteran reliever was notably trusted with preserving the one-run lead the Athletics had forged in the top half of the inning, so it appears manager Bob Melvin is still willing to deploy Casilla in high-leverage scenarios. The 37-year-old has put together five straight scoreless efforts, recording six strikeouts and allowing just two hits in five innings across that span.

Casilla fired a scoreless ninth inning in Wednesday's 6-1 win over the Giants, issuing a walk and recording a strikeout.

EDGE Analysis

The veteran right-hander has three straight scoreless efforts after having blown his sixth save opportunity of the season against the Blue Jays last Wednesday. Casilla's current status as closer is unknown at this point, as manager Bob Melvin opted to use Blake Treinen in the one save scenario since that point. In any event, Casilla has worked an inning apiece in three of the last four nights, so there won't be any definitive insight into Melvin's thinking on the subject over the next couple of games at minimum.

Casilla fired a scoreless eighth inning in Sunday's 6-5 extra-inning win over the Twins, recording a strikeout.

EDGE Analysis

The 37-year-old has now put together a pair of scoreless efforts following his latest implosion in the closer's role, which unfolded last Wednesday. The veteran right-hander had seen action in Saturday's one-run victory as well, although that had come in the seventh inning. His use in non-save scenarios in his last two appearances doesn't necessarily signify that he's out of the closer's role permanently, but manager Bob Melvin is clearly evaluating other options at the moment.