The Warriors have asked fans to wear green in celebration of the goalkicking winger's landmark appearance against Catalan Dragons at the DW Stadium on Friday night.
Richards, who is set to represent Ireland in the World Cup later this year, will go into the match needing one more try to reach 150 for the club and to climb into the top 10 of Super League's all-time tryscorers.
The popular Richards, who turned 31 last month, is in his eighth season in Super League, having made his debut against the Catalans in a 38-30 defeat in Perpignan in the French side's inaugural match in February 2006.
"Pat has been here that long I see him as a Wiganer," said Warriors coach Shaun Wane. "He is a great player and he loves playing for the club. Pat has been real quality and I think on Sunday at Castleford it was his best game of the season for us."
Richards, who has scored tries in six of the last seven home league games against the Dragons, said: "That is good to hear coming from Mr Wigan himself. I have been here a long time. It just goes to prove how much I love the place, I just keep extending my contract every time."
The winners of Friday night's game will go top of the table if Huddersfield lose at Leeds.
Both Warrington and St Helens go into the derby at the Halliwell Jones Stadium looking to bounce back from defeat.
Saints' loss to Leeds a week ago leaves them still looking for a first home win while the Wolves' relinquished their unbeaten record at Hull KR.
In Friday's other matches, Widnes and Bradford will be looking to post back-to-back wins when they meet at the Halton Stadium, while Hull and Castleford will be looking to get back to winning ways at the KC Stadium.
- Sports & Recreation
- Super League
- Catalan Dragons