"I'm going to let (Steichen) call it," Lynn said. "I do not want him looking over his shoulder for any reason."
Lynn described the 34-year-old former quarterback as "innovative," a "good communicator" and having "a lot of juice."
Steichen has a close relationship with quarterback Philip Rivers, which both Rivers and Lynn say will be beneficial to the offense moving forward.
Rivers said that Steichen has "great feel" (for football) and that the pair are "very much on the same page" and "talk all the time (about) the ins and outs of everything."
"(Rivers and Steichen) have good chemistry," Lynn added, "so I'm sure that's going to make it a smoother and easier process for (Steichen)."
While Sunday's matchup with the Packers will be Steichen's first time officially calling plays in a game, both Lynn and Rivers said they were not concerned.
"Shane (lacks) experience calling the plays, but (he does) not lack experience in his football knowledge (or) understanding of this system, both offense and defense," Rivers said. "Without actually doing it, he's been calling (plays) in practice for many years, so I think he's certainly prepared for this."
"I think Shane's been calling plays his whole life," Lynn added. "He just wasn't the coordinator."
Steichen's first NFL job came as a defensive assistant for the Chargers from 2011-2012. He then served as the Cleveland Browns' offensive quality control coach in 2013 before assuming the same role with the Chargers the following season. He became the Bolts' QB coach in 2016.
Though Steichen will be the Chargers' primary play caller Sunday, Lynn emphasized that he will be there to help as much as necessary.
"I may have to be a little more involved early on," Lynn said. "But as soon as Shane takes it and runs with it, it's going to be his baby. I just want to make sure he's okay and comfortable and just assist him with...what he may need."
Running back Austin Ekeler and Rivers each stressed that Steichen's presence and previously integral role will aid the transition.
"Shane's been like an extension of (Ken Whisenhunt) in my opinion," Ekeler said. "He knows the offense, (and) he has a great relationship with Phil, so I feel like he'll do a great job taking over."
Rivers said the offensive system will remain much the same, adding that Steichen had already been "heavily involved in the game planning week to week."
Lynn, who acknowledged that he's been in the same position as Steichen with taking over play calling for a team mid-season, shared the advice he has offered the young coach.
"Simplify," Lynn said. "Cut back and simplify, and let these young men play fast and physical, and (let them) know what the hell they're doing."