Richards flew home to Australia on Tuesday for his brother's wedding but is due to arrive back on Sunday morning - just hours before the Super League leaders' next match at the DW Stadium.
"He's the best man at his brother's wedding so I didn't want to stop that happening," Wigan coach Shaun Wane told the Wigan Evening Post. "He's been outstanding for me, his form this season has been the best I've known it in terms of consistency and this is a chance for me to repay him and support him."
Richards, Super League's Man of Steel in 2010, has scored 132 points in the first 10 matches to top the Super League scoring chart.
He is the league's leading goalkicker with 48 and is joint fifth in the try list, with nine touchdowns.
Wane said the 30-year-old has been given special instructions to follow to help reduce the impact of the long whistle-stop trip.
"He's got protocols with his diet and hydration and he's staying on England time," Wane added. "It's not a boozy wedding."