The New Zealand Warriors and Manly Sea Eagles will wear jerseys featuring #TheyAreUs in Saturday's match in Christchurch, in honour of the victims of the recent shooting attacks at two mosques in the city.
The hashtag references the words of New Zealand Prime Minister Jacinda Ardern following the attacks.
The teams will also take the field together and join arms in a circle to observe a minute's silence before Saturday's game.
Manly and Warriors players visited the Al Noor mosque on Friday to pay their respects to the victims of the Christchurch shooting tragedy.
"At the end of the day that does put it all into perspective. Any hardship that you feel like you are going through in life, you realise how insignificant it can be at times," Sea Eagles skipper Daly Cherry-Evans said.
"Footy is just a game but I'm glad it's a game that brings people together."
Manly coach Des Hasler said it was "very, very sad" being at the mosque to see where people had come to pray in peace and had that taken away.
Sea Eagles pay respects at mosque
The Warriors will continue wearing the #TheyAreUs hashtag on their jerseys for the rest of their home games in 2019.
"Like everyone, we were devastated with what happened a fortnight ago and we wanted to come up with a way to honour those who lost their lives," Warriors CEO Cameron George said.
"For us, it's a real privilege to be playing a game in Christchurch – a city that has been through so much.
Sironen hit hard by Christchurch tragedy
"Our community team and injured players have been on the ground since Wednesday and I know Stephen Kearney and the boys are determined to get down there and put in a fitting performance on Saturday for the locals who have been through so much."
Manly players were involved in a series of community events in Christchurch on Thursday, and Sea Eagles CEO Lyall Gorman said the club was proud to support the message of the hashtag.
Sea Eagles help bring smiles to kids of Christchurch
"What happened in Christchurch was beyond belief and our thoughts and prayers have been with the families and friends of those who lost their lives, and those who are still undergoing medical treatment," Gorman said.
"The people of Christchurch warmly embraced our club during our visit last year and we were incredibly humbled and honoured by it.
"In this time of real sadness, this is an opportunity for us to again be amongst the people of Christchurch and hopefully make some small contribution and difference to a healing process that is extraordinary in its nature."
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