From the main menu, go down to MyLeague and create a new file. Go ahead and accept all the way through the standard settings and select any team as the user team. Now just play the first game you're given. Press A on that date and select Simulate with Simcast Live. Decline any trades that may pop up. Once in the game, make sure to move the right stick to the right a few times to speed up the game to 6x.
That's it, now just walk away or do anything else for roughly 10-15 minutes and you'll get the achievement upon exiting at the end. You don't even have to select anything during the game or even call a timeout.