In the Friday morning pre-qualifying session, an Onyx topped the time sheets for the fourth Grand Prix in succession. Stefan Johansson was comfortably fastest, and his team-mate Bertrand Gachot also pre-qualified in fourth. Both drivers had re-signed with Onyx for 1990. For the first time this season, Piercarlo Ghinzani went through to the main qualifying sessions, in second place. For the third time this season, and for the first time since the US Grand Prix, he outpaced his Osella team-mate Nicola Larini, who missed out in fifth position. The Larrousse-Lola of Michele Alboreto was the other pre-qualifier in third, the Italian suffering from a cracked rib. His team-mate Philippe Alliot was down in sixth, the first time either he or a Larrousse had failed to pre-qualify.