Walker underwent surgery earlier this month due to a sore back that had been bothering him throughout spring workouts.
As a freshman in 2012, Walker recorded 11 receptions for 87 yards and was also used on special teams.
His absence will only complicate the departures of tight end Joseph Fauria and wide receiver Jerry Johnson, who were central to UCLA's passing attack a season ago.
Fortunately for the Bruins, they do return their leading receiver in Notre Dame transfer Shaquelle Evans and contributing sophomore wideouts Jordan Payton and Devin Lucien, who will likely see more action this fall without Walker.
The thinning of the depth chart could also provide the opportunity for one of many young, unproven Bruin wide receivers to step up.
Incoming freshmen like Eldridge Massington, who is given a 4-star rating by 247Sports.com, and 3- and 2-star players Jalen Ortiz and Darren Andrews could be given earlier chances for playing time than they originally thought.
Standing at only 5'9" and weighing 175 pounds, Walker was primarily used as a possession receiver. He averaged only 7.9 yards per catch in 2012, the second lowest of any UCLA receiver with at least ten receptions.
At 5'9" and 170 pounds, Ortiz and the 5'10", 175-pound Andrews could be inviting options for coach Jim Mora to replace Walker as short yardage targets. Meanwhile, Massington's 6'3", 205-pound frame might make him more suitable for the downfield passing game.
No matter who receives the playing time left by Walker, Mora will have to find an effective solution.
After the graduation of standout running back Johnathan Franklin and the Los Angeles Times reporting Pittsburgh's Rushel Shell's decision not to transfer after all, the ranks of Bruin running backs are not quite as deep. Combine that with the continued maturation of quarterback Brett Hundley and it appears that the passing attack will become more of a focal point for UCLA.
So even with Evans returning this fall, the development of role players at receiver looks to be gaining significance.