This info was presented to us by Laguna Seca PR man Reece White:

In order to defend the integrity of the racing surface and execution of the Grand Prix, FIM Race Direction has strongly recommended to the promoter that any other racing activity on Sunday, July 23 should be postponed until after the Grand Prix race.

The record temperature in combination with the fresh racing surface has created a situation that could potentially deteriorate with heavy usage on Sunday. Therefore, in order to safe guard the racing surface, the decision has been made to postpone the activities of the AMA Superbike series until the conclusion of the Grand Prix race.

The Grand Prix program will proceed as scheduled, with a morning warm-up at 10:00 am local time. The MotoGP World Championship race will begin at 2:00 pm local time.

The AMA Supersport and Superstock race will take place immediately following the MotoGP World Championship race.