That wasn’t the case two years ago, when Ekeler showed up at Chargers Park in San Diego as an undrafted rookie out of Division II Western State Colorado (whose school name has since changed to Western Colorado University).
Rivers kept asking backup quarterback Kellen Clemens: "Hey, what's No. 3’s name again?"
But Ekeler regularly made plays during offseason work and training camp in 2017, earning a spot on the 53-man roster. From there, Rivers learned his name.
"We got it going, and then I said, 'Shoot, this No. 3 is pretty good,'" Rivers said after the Chargers' 30-24 overtime victory over the Indianapolis Colts on Sunday. "And No. 3 ended up being No. 30, who we now know as Austin Ekeler. And he's been a playmaker for us over the last few years. I don't think anybody was surprised with the plays he made today."
Ekeler is making sure the rest of the league remembers his name as well.
Starting in place of Melvin Gordon, who’s in Day 48 of his holdout over a contract impasse with the Chargers, Ekeler finished with a career-high 154 yards from scrimmage and three touchdowns against the Colts. That total included the game-winning score on a 7-yard run in overtime.
According to ESPN Stats & Information, Ekeler gained 108 yards after the catch Sunday. His 10.4 yards per reception in 2018 led all running backs.
"He has this thing that nobody can see unless you're out there with him, but there's just nothing too big for him," Rivers said. "You can see it in his face and in his eyes and in his communication. It's just like we're out there in the backyard. I saw that when he was a young player, and that's continued to be the case."
Looking to replace the production of one of the top running backs in the NFL, Chargers coach Anthony Lynn said he would lean on a running-back-by-committee approach to start the season. It worked in Game 1.
Ekeler's big day included 95 receiving yards on six receptions. He and Justin Jackson combined for 115 rushing yards on 18 carries, giving the Chargers balance on offense.
At 5-foot-8 and 200 pounds, Ekeler isn't built like a traditional tailback. However, Lynn believes the 24-year-old can be a feature back in the NFL.
"He plays with outstanding leverage," Lynn said. "And like I’ve said before, pound-for-pound he is the strongest man on our team."
Added Ekeler: "Physically, I feel good. I think with my body type, I'm lower to the ground and take less hits through my ankles and knees. I think that's really going to help me out through my entire career as far as injuries."
Ekeler's versatility and Jackson's slithery running style were a couple of reasons Lynn, Rivers and the rest of the Bolts weren't too concerned about Gordon's absence. The Chargers have been successful with the Ekeler-Jackson combo, as they are 5-0 the past two seasons when Gordon hasn't played.
Yes, Gordon makes the Chargers better on offense, and they would like to have him back on game days. But since Rivers took over as the team's starting quarterback in 2006, the Chargers have finished outside of the top half of the league in scoring only twice in 13 seasons.
Different players have cycled through over the years, including running backs LaDainian Tomlinson, Darren Sproles, Danny Woodhead and Ryan Mathews, receivers Vincent Jackson and Malcolm Floyd, and tight end Antonio Gates. Also, the Chargers have been led by several offensive coordinators, including Norv Turner, Frank Reich and Ken Whisenhunt.
However, the Chargers' dedication to a balanced offense has stayed the same, according to Rivers. Ekeler is the latest back to lead the rushing aspect of it.
"It is our identity," Rivers said. "I do think that is who we wanted to be for the last 15 years. If you look offensively for the last 15 years, we played best when we were balanced.
"We've had rushing leaders. We won rushing titles, and those are the years we played the best, but within those seasons, we have games where you throw it 40 times and find a way to win. When we are balanced, there is no question that is when we play our best. That is who we are. We're not a spread-it-out, dink-and-dunk team. We are a balanced team."