His improvement has been a testament to the work he's put in, and quarterback Justin Herbert was one of the many who were thrilled for the wide out.
"I'm really happy for him. He's earned it," Herbert said about Johnston earlier in the month. "He's worked so hard and think so highly of him as a receiver, as a teammate, as a locker room guy. I think he's going to have his best year.
"He's done such a great job of picking up this offense, playing football and playing fast," Herbert added. "I'm really excited to see what he can do this year."
All eyes now turn to what Johnston is capable of in this new Mike McDaniel offense with the Chargers.
The Chargers Offensive Coordinator has been working with the unit during the spring as the process begins of installing the new offense.
The changes, as McDaniel has explained throughout the last couple of months, focus on timing and attacking things with speed among many other things have been adjustments all receivers have worked on so far.
Johnston said he's enjoyed working closely with the new playcaller.
"I'm not going to say I do it differently, but some of the routes just working on timing as far as out of break stuff," Johnston said. "Just getting my head around with different stuff quicker. As far as running routes, it's not that much that I feel like he even wanted to tweak with me.
"He liked my stride, he liked my running, he was just like keep doing that and as far as the plays, he's going to put me in the right position to be successful," Johnston added.
One of the biggest things that could spell good things for Johnston is what McDaniel's offense allows receivers to do after the catch.
Johnston showed his prowess in yards after the catch while at TCU and becoming one of the best in the country at it. Almost half of his receiving yards in his final collegiate season came after the catch (532 of 1,068 yards).
It's safe to say that's something he's really excited about to have the opportunity to do more of.
"I feel like the scheme he has is set up for the yards after catch," Johnston said. "There's not always a lot of room for that in this league but just showing us different angles and stuff to get to the ball after the catch and turning, going across field and doing different stuff in the plays he has built for us."
Johnston later added: "In college, I was a big yard after catch guy so when he introduced some of those things to us during meetings and at practice, it lit me up a little bit. I'm really fired up about that."