| Starter | Tm | Tier | Game |
|---|---|---|---|
| Orel Hershiser | LAN | 6.49 | 198909030_WAS_LAN |
| Bret Saberhagen | KCA | 5.92 | 198909040_KCA_DET |
| Mike Moore | OAK | 4.86 | 198909040_BOS_OAK |
| Bert Blyleven | ANA | 4.05 | 198909030_ANA_NYA |
| Ed Whitson | SDN | 3.54 | 198909040_SDN_ATL |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Melido Perez | CHA | -4.25 | 198909030_BAL_CHA |
| Andy Hawkins | NYA | -2.68 | 198909030_ANA_NYA |
| Jack Morris | DET | -2.05 | 198909030_CLE_DET |
| Storm Davis | OAK | -1.38 | 198909030_OAK_MIL |
| Pete Smith | ATL | -1.2 | 198909030_CHN_ATL |
Based on accumulated WAA for this season up to 1989-09-05.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +004+ | 6.59 | Orel Hershiser | 219 | LAN |
| +007+ | 6.26 | Bret Saberhagen | 215 | KCA |
| +009+ | 5.59 | Chris Bosio | 217.7 | MIL |
| +014+ | 5.28 | Mike Moore | 208 | OAK |
| +013+ | 5.28 | Scott Garrelts | 155.7 | SFN |
| +017+ | 5.11 | Chuck Finley | 176.3 | ANA |
| +018+ | 5.08 | Mark Gubicza | 237.7 | KCA |
| +021+ | 4.8 | Bert Blyleven | 204 | ANA |
| +025+ | 4.55 | Rick Reuschel | 176.3 | SFN |
| +030+ | 4.41 | Ed Whitson | 201.7 | SDN |
| +031+ | 4.4 | Greg Maddux | 205 | CHN |
| +033+ | 4.27 | Bryn Smith | 186 | WAS |
| +034+ | 4.26 | Mark Langston | 218.3 | TOT |
| +036+ | 4.13 | Joe Magrane | 205.3 | SLN |
| +037+ | 4.11 | Sid Fernandez | 183 | NYN |
| +039+ | 4.08 | Doug Drabek | 212 | PIT |
| +042+ | 3.76 | John Smoltz | 209.7 | ATL |
| +044+ | 3.72 | Bob Welch | 178 | OAK |
| +045+ | 3.7 | Mike Morgan | 147.7 | LAN |
| +048+ | 3.64 | Bruce Hurst | 207.3 | SDN |
| +049+ | 3.62 | John Cerutti | 180 | TOR |
| +053+ | 3.43 | Tom Browning | 222.7 | CIN |
| +060+ | 3.22 | Kirk McCaskill | 176.3 | ANA |
| +062+ | 3.2 | Jose DeLeon | 214 | SLN |
| +064+ | 3.18 | Dennis Martinez | 207.7 | WAS |
_