The actor was killed in a car accident in November, 2013, just weeks before wrapping filming for the seventh installment of the blockbuster franchise.
Promotion for Furious 7 has already begun ahead of its 3 April (15) release date, but Rodriguez and Gibson have mixed emotions as they travel the world without Walker by their side.
Gibson tells Access Hollywood, "It's the most uncomfortable press junket any of us have ever done, because obviously... it's my first time ever being a part of a movie where someone I know and love is on the poster and they're not there. It’s almost like, just release the movie and we'll stay at home, because to be smiling on red carpets or doing interviews is hard."
Rodriguez adds, "Pretending everything is just fine and dandy... it's not real, you know?"
On Friday (27Feb15), the pair feted Walker's younger brother Cody Walker, at the 2015 Noble Awards in Beverly Hills, where he received an award for quitting his job as a paramedic in Oregon and moving to Los Angeles after his brother's death to continue Paul's work with the humanitarian relief organisation he founded, Reach Out Worldwide.
Cody choked back tears as he accepted the prize from Gibson and Rodriguez, as well as his older brother Caleb Walker.
He tells Access Hollywood, "What this means for us is that so many other people loved Paul and loved the work that he was doing. And we just feel the love by being here and being a part of this and being honoured by this. It just makes it super special."
The two siblings joined the Fast & Furious cast to act as stand-ins for their late brother to help complete filming on Furious 7, and Caleb acknowledged he is glad to be doing the difficult press tour with Cody, saying, "There have been mixed emotions during filming and press has been so intense, but you feel it's nothing but positive energy.
"It's been challenging, but being able to spend more time with Cody has meant more now than ever."