Tight end Michael Mayer signed a contract extension with the Las Vegas Raiders on Saturday. Mayer agreed to a three-year, $45 million deal with $30 million guaranteed, according to a person with knowledge of the contract. The person spoke to The Associated Press on the condition of anonymity because the terms weren't announced. Mayer likely will start Sunday’s season opener when Miami visits Las Vegas. Top tight end Brock Bowers is out because of a knee injury.