According to a report from "Cyclingweekly", Peter Sagan has offered his starting place in the Olympic road race in exchange for a starting place in the mountain bike race. Sagan does not think he has a chance of winning on the road due to the difficult course - in the mountain bike race, the former junior world champion is hoping for a precious metal. The Slovakian Olympic Committee has now agreed to a swap and has officially called Sagan up for the mountain bike race. Martin Haring, who was selected for the mountain bike race, will start in the road race - Peter Sagan will take his quota place in the mountain bike starting field. Michal Lami, who is ranked higher in the world rankings, was booted out. However, Sagan has to start far back in the field due to his few UCI points - the road to the top will be long and Sagan will probably not voluntarily make room for another rider.

Link to the page of the Slovakian Olympic Committee, but the news report is only in Slovakian:
https://www.olympic.sk/aktuality-sov/peter-sagan-bude-na-oh-v-riu-startovat-v-horskej-cyklistike-na-ceste-sa-predstavi-martin-haring