Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 02/1991 |  | Jesualdo Ferreira | MA | |||
| 07/1990 | | Jorge Vital | GK |  | Sporting CP | Sporting |
| 07/1990 | | Álvaro | DF |  | SL Benfica | Benfica |
| 07/1990 | | Dimas | DF |  | Académica de Coimbra | Académica |
| 07/1990 | | Valério | DF |  | Boavista | Boavista |
| 07/1990 | | Francisco Agatão | MF | | Boavista | Boavista |
| 07/1990 | | Marito | MF |  | FC Porto | FC Porto |
| 07/1990 | | Miranda | MF |  | GD Chaves | GD Chaves |
| 07/1990 |  | Abel Campos | FW | | SL Benfica | Benfica |
| 07/1990 | | Mendes | FW |  | Louletano | Louletano |
| 07/1990 | | Sérgio | FW |  | Sporting Covilhã | Covilha |
| 07/1990 | | Manuel Fernandes | MA |  | Vitória Setúbal | Vitória FC |
| 07/1990 | | José Mourinho | AS-CO |  | Vitória Setúbal U19 | Vitória Setúbal U19 |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 07/1990 | | Álvaro | GK | | Boavista | Boavista |
| 07/1990 | | Barny | DF | | Boavista | Boavista |
| 07/1990 | | Caetano | DF | | Boavista | Boavista |
| 07/1990 |  | Chico Oliveira | DF |  | CS Marítimo | CS Marítimo |
| 07/1990 |  | Bobó | MF | | Boavista | Boavista |
| 07/1990 | | Jaime Cerqueira | MF | | Boavista | Boavista |
| 07/1990 |  | Basaúla Lemba | MF |  | Vitória Guimarães | Vitória SC |
| 07/1990 | | Ricardo Lopes | FW |  | FC Penafiel | Penafiel |