According to Daytona International Speedway's official Twitter feed, Cena will be at the race on Monday to wave the green flag. He will also replace Kate Upton and Jane Lynch as Grand Marshall, since the two of them left town after the rain delay. Cena will become the first person in the history of the race to be Grand Marshall and Honorary Starter. Cena will give the command to start engines on pit road then get taken over to the start/finish line and climb the flag stand to wave the green flag.
The weather forecast for Monday's race could still see more rain, meaning the race could be delayed from noon to later in the day. If that were to be the case, Cena would definitely have to leave early. However, Cena's rep told TMZ that Cena will still make his scheduled appearance on RAW in Portland.
The plan as of right now is to have Cena wave the green flag and then immediately head to an airport near Daytona. He'll fly out of Daytona and get to Portland, OR a few hours before RAW if everything goes according to plan. He'll then take a limo/car to the Rose Garden Arena arena, quickly review the script and then appear live. Needless to say, tomorrow will be a VERY interesting day for Cena.
Apparently, he refuses to appear "via satellite"!