In 2019, Mike Trout signed a 12-year, $430 million contract. This is on the heels of Bryce Harper signing a 13-year, $330 million contract. There have been several 10-year contracts signed by baseball players.
The longest contracts in the NFL during the 2018-2019 season are 6 years in length. The longest contracts in the NFL during the 2000s were 8-12 years in length.
Are 10+ year contracts discouraged or prohibited in the NFL? If discouraged, why? There were a few NFL contracts in the 10+ year range in the 2000s, but none since.