"He does such a great job of commanding the communication, the calls," McVay says."He sees the game from a 22-man perspective."
Sullivan, who sports a black beard that features flecks of gray, was one of several offseason additions the Rams made to upgrade their offensive line. Left tackle Andrew Whitworth, 35, was brought in to protect Goff's blindside, and he has played well for a unit that has given up only 20 sacks, seventh fewest in the league.
But it's Sullivan, coaches and teammates say, who has become a coordinator on the field. Before each snap, Sullivan analyzes defenses and communicates to teammates.
"The sport is a lot easier if you know what you are looking at right in front of you, rather than just having to be reactive to what's going on," Sullivan says.
Sullivan makes "everybody's life so much easier, just understanding the game," running back Todd Gurley says, noting that Sullivan is equally helpful in the film room. "He's been so well prepared, getting us prepared."
No player has benefited from Sullivan's presence more than Goff, who has passed for 20 touchdowns with six interceptions.
"It takes a lot off my shoulders for sure," Goff says, "with his ability to understand defenses and make a lot of calls up front."
Sullivan and Goff understand that the quarterback has the final say at the line of scrimmage, but there rarely is a power struggle.
"If I see something, and overrule, I can," Goff says, adding, "99 percent of the time he's right."
Sullivan has been happy to see Goff mature and improve "in terms of what he is able to see, his reads and everything" in the eight months they have been teammates.