| Starter | Tm | Tier | Game |
|---|---|---|---|
| Roger Clemens | BOS | 9.01 | 198904300_BOS_TEX |
| Frank Viola | MIN | 4.16 | 198904290_CLE_MIN |
| Mike Scott | HOU | 4.13 | 198904300_NYN_HOU |
| David Cone | NYN | 3.4 | 198904300_NYN_HOU |
| Charlie Leibrandt | KCA | 3.38 | 198904280_MIL_KCA |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Mike Birkbeck | MIL | -2.08 | 198904300_MIL_KCA |
| Bill Long | CHA | -2.04 | 198904290_CHA_NYA |
| Mike Witt | ANA | -1.55 | 198904300_TOR_ANA |
| Todd Stottlemyre | TOR | -1.47 | 198904280_TOR_ANA |
| Ken Howell | PHI | -1.26 | 198904300_CIN_PHI |
Based on accumulated WAA for this season up to 1989-04-30.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +001+ | 2.49 | Kirk McCaskill | 36.7 | ANA |
| +004+ | 2.13 | Chris Bosio | 39.3 | MIL |
| +005+ | 1.98 | Jose Rijo | 31 | CIN |
| +006+ | 1.85 | Jeff Ballard | 37 | BAL |
| +007+ | 1.71 | John Cerutti | 32 | TOR |
| +011+ | 1.6 | Roger Clemens | 45.7 | BOS |
| +012+ | 1.58 | Jose DeLeon | 41.3 | SLN |
| +014+ | 1.5 | Scott Terry | 35.3 | SLN |
| +018+ | 1.44 | John Smiley | 36.7 | PIT |
| +017+ | 1.44 | Rick Mahler | 34.7 | CIN |
| +019+ | 1.43 | Mike Morgan | 25 | LAN |
| +020+ | 1.41 | Doug Drabek | 36.3 | PIT |
| +022+ | 1.39 | Doyle Alexander | 39.3 | DET |
| +026+ | 1.37 | Orel Hershiser | 37 | LAN |
| +025+ | 1.37 | Mike Moore | 33 | OAK |
| +028+ | 1.35 | Steve Ontiveros | 20 | PHI |
| XXXXX | 1.24 | Nolan Ryan | 35 | TEX |
| XXXXX | 1.24 | Allan Anderson | 31 | MIN |
| XXXXX | 1.2 | Tom Glavine | 38 | ATL |
| XXXXX | 1.16 | Erik Hanson | 32.3 | SEA |
| XXXXX | 1.14 | Dwight Gooden | 37.7 | NYN |
| XXXXX | 1.12 | Bob Welch | 35 | OAK |
| XXXXX | 1.1 | Dave Stewart | 42 | OAK |
| XXXXX | 1.08 | Bert Blyleven | 37.3 | ANA |
| XXXXX | 0.98 | Walt Terrell | 33.3 | SDN |
_