He had only 33 catches during the regular season with zero touchdowns. The postseason didn't begin much better with one catch for 10 yards in a 49-37 victory over Minnesota.
Then came the NFC Championship Game.
Tampa Bay clamped down on star receivers Torry Holt and Isaac Bruce. Proehl responded with six catches for 100 yards, including a 30-yard touchdown with 4:44 remaining to give the Rams an 11-6 victory that they followed up with a win in the Super Bowl.
Be ready. You never know when your number will be called.
Proehl, now in his first season as the wide receivers coach for Carolina, has preached that message to what, for the most part, is a group of role players as the Panthers prepare for Sunday's NFC playoff game against the San Francisco 49ers.
"To me, it's such a mental game as much as it is a physical game," Proehl said. "And if you're not ready mentally, if you're getting down and frustrated, it affects the way you play, the way you run a route and ultimately your production.
"That's the thing I try to teach these guys."
You might be wondering why Proehl is the focus here, heading into Carolina's first playoff game since 2008. The answer is simple.
What Proehl represents for a group of receivers that has struggled the past few weeks while star Steve Smith recovers from a left knee sprain, for a group that struggled in a 10-9 victory over San Francisco in November, is important.
It's not about who makes the play. It's about somebody making a play. It's about being ready. It's about doing little things, such as blocking and running precise routes, that make the rest of the offense work.
In some ways, Proehl is Carolina's secret weapon. He has a knack for teaching receivers, young and old, tricks that enable them to get separation and be in position to make plays.
Even on great teams like the Rams, stars such as Holt and Bruce came to him for advice. Smith noticed immediately when Proehl came to Carolina as a player in 2003 -- the year the Panthers went to the Super Bowl -- that he had a rare understanding of routes and coverages that made everybody better.
With Smith's knee not 100 percent, being precise in the things Proehl has taught him could be the difference Sunday.
"Not everybody can do some of the things Ricky can do and the way he can teach," Smith said. "It's hard to explain, but all I can say is that it's a gift. It's not forced. It's just natural. He does it in a unique and great way."
Proehl's 669 career catches for 8,878 yards in 17 seasons pale in comparison to Smith's 836 catches for 12,197 yards in 13 years. But to hear Smith, it's Proehl who had the Hall of Fame-worthy career.
"I don't care how old you are," Smith said. "The information Ricky has, you can use. I'll be able to use this when I'm at the rec league. It's football. It's using the advantage of what you have and using the disadvantages of the defense."
San Francisco doesn't have many weaknesses on defense, ranked seventh against the pass and fifth overall. So any weakness Proehl finds will be key.
"He's good on game day with good suggestions," offensive coordinator Mike Shula said. "[And] not just on game day, but over the course of the week. Not just overall in the passing game, but individual routes versus individual backs."
In other words, Proehl is precise.
"Yeah, he's very precise," Shula said with a smile.
Proehl, 45, also is an example for a team that had three straight losing seasons before this one. He spent his first five NFL seasons with the Cardinals, with no record better than 8-8. His best record in two years at Seattle was 8-8. Next was a 4-12 year at Chicago. Proehl's first season in St. Louis, 1998, was another 4-12 nightmare.
Then came 1999, a 13-3 regular season that turned into a Super Bowl ring. From 1999 to 2005 -- the last three with the Panthers -- Proehl went to three Super Bowls and the NFC Championship Game four times.
He taught Smith and other veterans that good things can happen at the end of your career. He taught young players not to get impatient when things don't go right early.
That's why Brandon LaFell, the team's No. 2 receiver, hasn't gotten down after catching one pass in the last game and three quarters with Smith out. That's why Ted Ginn Jr. has been able to resurrect a career as a receiver when it looked like he was destined to be a return specialist.
That's why the Panthers aren't worried about their passing game as much as one might think they should be.
"Oh, man, he's meant a lot to me," Ginn said of Proehl. "A guy that's had faith in me, a guy that played the game, [who] wasn't caught up in who was in his [receivers] room.
"You can never tell who in our room is who," Ginn continued, explaining that Proehl doesn't differentiate between his starters and the reserves. "That's why we love our room. That's why Coach Proehl is who he is."
That's why Proehl is the topic here as the Panthers prepare for a game where most of the focus is on quarterback Cam Newton and Carolina's second-ranked defense.
He was a player who never quit on a team -- just as these Panthers didn't quit when they were 1-3.
"That's the biggest thing, being selfless," Proehl said. "That's what this team is all about. We don't care who gets the glory, who gets the paper clippings. It's all about winning, and at the end of the day, you win as a team."