| Starter | Tm | Tier | Game |
|---|---|---|---|
| Orel Hershiser | LAN | 6.99 | 199004190_HOU_LAN |
| Joe Magrane | SLN | 4.55 | 199004190_PIT_SLN |
| Ted Higuera | MIL | 3.16 | 199004210_BOS_MIL |
| Frank Viola | NYN | 3.05 | 199004210_WAS_NYN |
| Rick Reuschel | SFN | 2.72 | 199004200_SFN_SDN |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Jim Clancy | HOU | -3.61 | 199004210_HOU_LAN |
| Oil Can Boyd | WAS | -3.01 | 199004210_WAS_NYN |
| Todd Stottlemyre | TOR | -2.45 | 199004200_KCA_TOR |
| Walt Terrell | PIT | -2.12 | 199004200_PIT_CHN |
| Bobby Witt | TEX | -1.92 | 199004190_MIL_TEX |
Based on accumulated WAA for this season up to 1990-04-21.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +001+ | 1.87 | Teddy Higuera | 20.3 | MIL |
| +002+ | 1.65 | Dennis Cook | 20.3 | PHI |
| +003+ | 1.54 | Chris Bosio | 19 | MIL |
| +005+ | 1.31 | Kevin Tapani | 19 | MIN |
| XXXXX | 1.23 | Jack Armstrong | 19 | CIN |
| XXXXX | 1.23 | Chuck Finley | 14.3 | ANA |
| XXXXX | 1.16 | John Tudor | 13 | SLN |
| XXXXX | 1.09 | Frank Viola | 22.3 | NYN |
| XXXXX | 1.03 | Pascual Perez | 11 | NYA |
| XXXXX | 1.02 | Zane Smith | 21 | WAS |
| XXXXX | 0.98 | John Dopson | 10.7 | BOS |
| XXXXX | 0.95 | Bob Welch | 18.7 | OAK |
| XXXXX | 0.91 | Dave Stieb | 17 | TOR |
| XXXXX | 0.86 | David West | 18.7 | MIN |
| XXXXX | 0.82 | Kirk McCaskill | 12 | ANA |
| XXXXX | 0.8 | Dave Stewart | 19.3 | OAK |
| XXXXX | 0.77 | Dan Petry | 13 | DET |
| XXXXX | 0.75 | Mike LaCoss | 20 | SFN |
| XXXXX | 0.74 | Neal Heaton | 12.7 | PIT |
| XXXXX | 0.72 | Dennis Martinez | 20 | WAS |
| XXXXX | 0.7 | Mike Morgan | 14.7 | LAN |
| XXXXX | 0.68 | Storm Davis | 12.3 | KCA |
| XXXXX | 0.66 | Greg Maddux | 14.7 | CHN |
| XXXXX | 0.63 | Brian Holman | 21 | SEA |
| XXXXX | 0.52 | Ed Whitson | 15 | SDN |
_