Providing he plays against former side Cronulla next week, Johnson is set to retire at the end of the season as a veteran of 268 NRL games - 224 of those for the Warriors - and finish his career as the club's most significant playmaker since Stacey Jones.
The 33-year-old will first run out at Mt Smart Stadium, to be renamed Shaun Johnson Stadium, for the final time when the Warriors host a resurgent Canterbury on Friday night.
A sold-out crowd will be on hand to see off the man who helped push the Warriors to their most recent grand-final appearance in 2011, and inspired a generation of Kiwi kids to pick up the footy with his colourful style of play.
"It's going to be a huge occasion," coach Webster said as the Warriors also prepare to farewell departing forwards Addin Fonua-Blake and Jazz Tevaga.
"One, we love playing here. We've sold out every game. It's probably our opportunity to say thank you to those three boys and to the fans. There's a lot to play for."
Webster said he had been personally impacted by "all three" of Johnson, Sharks-bound Fonua-Blake and Tevaga not offered a contract for 2025.
Working with Johnson has influenced Webster's tactical outlook on the game.
"When you work with an elite halfback like that, the conversations you have around rugby league can shape the way you do things and want to play," Webster said.
"Shaun's certainly had that.
"Shaun has been unbelievable for this club and I've said it before, just for the game in general. Super happy for him and I hope we send all three of them out on the right note."
As Johnson's career comes to a close, having been hampered by injuries this year, so too does the curtain fall on a disappointing season for the Warriors.
Webster took the Auckland side to their first top-four finish since 2007 in his first season in charge, but his second never truly recovered from a slow start.
In total, the 14th-placed Warriors lost seven games by six points or fewer this season, the most of any team, with two of those coming in golden point.
But Webster would not accept excuses as a "not great" season approached its conclusion.
"We wanted to achieve more. We haven't played as well as we can, that's the frustrating bit," he said.
"A lot of people have said to me, 'if you had've won a couple more games, so close, you were so hard done by'.
"But I think in the pit of our stomach we all know that we haven't played the way we wanted to. That's on us to get it right next year."
