Rank History
| Year | Team | Position | Team Rank | OFP |
|---|---|---|---|---|
| 2021 | SF | RHP | 29 | 40 |
Grades Update: Apr 2021
| OFP | Role | FB | CB | CH | Cnt/Cmd |
|---|---|---|---|---|---|
| 40 | 40 | 55 | 60 | 50 | 60/55 |
Apr 2021 Report
Evaluator: Danny Brackman
Age: 23 yr
Height: 6-4
Weight: 225 lbs
Hits/Throws: R/R
Acquired: 2018 Round 4
RuleV: 2021
Physical Description: Big athletic build. Very strong lower half with a thick core and broad shoulders. Good functional mobility but can look stiff at times.
Delivery & Mechanics: Windup starts off-set towards 1B edge of the rubber. Uses a medium high leg-kick to stack trunk and begin downhill move. Reaches back with upper half, possibly a bit too far, to create separation, generating above average power and arm speed from an over-the-top slot. Not an overly long arm action that helps repeatability, though the posture issue created does alter mechanical efficiency through some clear timing issues. Stretch starts with front foot/hip closed off which appears to help stay stacked more naturally.
Fastball: 92-95 and can reach back for 97. Above average velo and near elite raw spin but below average movement profile due to heavy cutting. Cut does help induce a high GB% but doesn't offer much whiff potential due to command issues. Velo does tend to dip later in outings. Improving spin efficiency would likely help both feel and movement, showing there's still a gap between current offering and future potential. Grade: 55
Curveball: 79-83 with massive, sharp vertical break. Another high spin offering but the efficiency does appear to be better. True CB axis that plays plus virtually anywhere in the zone. Strong swing and miss offering down to both LHHs and RHHs. Does flash a legit double-plus hammer at times though command presently caps ceiling. Grade: 60
Changeup: Mid-80s with above average fade. Over-the-top slot makes it difficult for hitters to pick up and comfort throwing it has improved. Doesn't throw it as much as he could, likely due to still developing feel, though he does show confidence by sprinkling in some nice same-handed CHs to mix things up. Movement profile and recent improvements suggest potential for at least an average third offering. Grade: 50
Control and Command: Seems to have better feel with secondaries than the FB. FB cut combined with mechanical deficiencies create a hill to overcome to get the most out of the offering. Can keep it down away from barrels but struggles to hit spots consistently. Does an average job keeping the CB down to generate whiffs but will leave plenty up in hittable areas. Surprisingly good feel for keeping the CH arm-side. Control: 40 | Command: 30
Overall: Rivera has been tested as a starter since going pro, though it's looking more and more likely that he's destined for a future as a reliever. He performed well in 2019 and made strides towards remaining a starter, but he'll need to improve his fastball profile and mechanical efficiency if he wants to do so. His stuff would likely play up in short stints anyway, where he has less time to lose feel and can just lean on his CB, making a return to the pen the most obvious outcome.
OFP: 40
Role: 40 - Low-Leverage Reliever
Risk: High
