Read an article that the reason he hasn't signed his rookie contract is because it limits his abilities to go surfing even during the off season. Could you imagine if this was Jameis?
http://national.suntimes.com/national-sports/7/72/1398356/marcus-mariota-titans-contract-surfing
http://national.suntimes.com/national-sports/7/72/1398356/marcus-mariota-titans-contract-surfing