SAN DIEGO -- Antonio Gates and Philip Rivers have played impressively together over the last decade and now head into the twilight of a symbiotic relationship on the field.

Even though Gates entered 2016 as an unrestricted free agent, there was little doubt he would return to the San Diego Chargers this offseason. Gates inking a two-year, $12 million deal to remain in San Diego was not a surprise.

“Our relationship is unbelievable,” Gates said about playing with Rivers. “I’ve been fortunate enough to play with some great guys, some great talent. But the thing about Philip is one word really can’t describe him. He’s a talented guy with a competitive edge. His leadership ability is second to none.

“I’ve been fortunate enough to be with him throughout the duration of his career here. And I’d rather not play for another guy or catch from another quarterback at this point.”

Although the tight end turned 36 in June, Rivers said during minicamp this summer that Gates can still consistently get open.

“There’s still such a suddenness there, even at the age of 36,” Rivers said. “He still looks fast. He’s sharp.”

However, the Chargers drafted Hunter Henry in the second round of this year’s NFL draft to be Gates’ eventual replacement for a reason. Gates is near the end of a remarkable NFL career.

Regardless, he should still put up decent numbers this season.

After missing the first four games of last season due to a suspension for violating the NFL’s policy on performance-enhancing drugs, Gates limped through the second half of 2015 following an MCL knee sprain in a Week 6 loss against the Green Bay Packers. Despite the suspension and being slowed by injury, he finished the season with 56 catches for 630 yards and five touchdowns.

This season, Gates is out to prove that he can still make game-changing plays that lead to victories for San Diego.

Gates also has a reachable milestone this season. With 104 career touchdown catches, he needs eight more to move ahead of Tony Gonzalez (111) for sixth in NFL history and first among tight ends.

Rivers has said that along with turning things around for the Chargers as a team, helping Gates reach that mark is a goal in 2016.

Over the last five years, Gates has averaged 63 catches, 728 yards and seven touchdowns per season. Even with the addition of Henry, it’s a reasonable expectation for Gates to record similar numbers in 2016 if he stays healthy.