EVERY SUMMER, Brent Celek and his brother Garrett, now a rookie tight end with the 49ers, get together and talk football. Now in his sixth NFL season, Brent plays the role of mentor. If he is as good a teacher as Garrett says he is, he will probably spare his brother any lessons born of this season of Eagles football.

Like many of his Eagles teammates, this year has been one to forget for Celek. Whether dropping passes or absorbing bone-crunching hits, the veteran tight end has not been his reliable self in months.

In Week 11, a Nick Foles pass intended for Celek bounced off his hands and into those of DeAngelo Hall, setting up the Redskins' first score. Two weeks before that in New Orleans, a defender took a Celek deflection 99 yards for a touchdown. Both instances - each in the first quarter - were devastating blows from which the Eagles never recovered.

Despite his struggles, the effort and accountability has always been there during Celek's tenure in Philadelphia. Nothing has changed. Frustrated after the loss to the Redskins, he fired off a series of apologetic tweets:

"I'm sick about this crap. Philly is my home. I feel like I'm letting my family down," he said via Twitter, adding, "No matter what y'all say I know I have let y'all down. Life's about stepping up when it counts."

From the players' perspective, the loss to the Redskins was the deathblow for a team that fans lost confidence in months ago. Celek's words echoed that sentiment. The subsequent losses to Dallas and Carolina have only made things worse. Luckily for Brent, the emergence of Garrett as an NFL player has provided a silver lining to what is a lost season.

"Honestly, I couldn't be more proud of him," Brent said. "For what he has done - playing offensive tackle in high school, not really playing football in grade school and then going to college - to be able to make it to the NFL level, it just goes to show you what hard work can do."

As younger brothers tend to do, Garrett has emulated Brent's every move. He moved from offensive line to tight end in college. He committed to Brent's alma mater at Cincinnati, only to follow Mark Dantonio, Brent's former coach, to Michigan State. He went undrafted but stuck on a talented 49ers team, joining his brother in the NFL.

Garrett has been active for eight of San Francisco's 12 games. He is still learning the position, but at 6-5 and more than 250 pounds, he has the same size and toughness that has made Brent a success in the NFL (Brent is 6-4, 255). After catching only 14 passes in 4 years at Michigan State, Garrett, like many undrafted free agents, was a longshot to make a team. But with his brother's help, he did.

"He was just telling me to work hard," Garrett said. "Realistically I wasn't going to get drafted due to my performance in college, so I had to make a team. He was telling me I have to really show off in front of these coaches because I don't have a lot of background."

Brotherly competition aside, Brent is the first to lavish his brother with praise. While Brent won't admit it, his success in the NFL paved the way for Garrett to follow in his footsteps. When the 49ers' final cuts were announced in August, it had all come full circle.

"I called him," said Brent, the oldest of five Celek siblings. "I just couldn't be happier for him as his brother. Sometimes when you have brothers and sisters all younger, you hope better things happen to them than they do you almost."

After playing left tackle in high school, Garrett moved to tight end at Michigan State, where he was utilized primarily as a blocker. Knowing that he had to improve as a receiver to extend his career, he turned to Brent. School has been in session ever since.

"When we get together, we definitely talk football, talk concepts, certain routes, things you can do," Garrett said. "After all my games at Michigan State, he would give me a call and tell me what he saw, what I needed to do better."

Within the season, Brent scales back his input in deference to Garrett's coaches, especially now that they're in the NFL. But once the year is over, it is right back to coverages, route-running and chip-blocking. And when they grow tired of that, they go back to being brothers.

Competitive brothers.

"He keeps telling me he is going to get a Super Bowl ring before me," Brent said, adding that he always replies the same way. "I tell him if he does, I will retire."

With the 49ers headed back toward the playoffs and the Eagles in disarray, Brent may want to start rephrasing that response. Or at least hope that the Niners fall short, so he can get his revenge on the field. At the latest, the Eagles and 49ers will meet in 2014.

"I will ask to play defensive end," Brent chuckled. "So I can just knock his head off."