|By Simon Stone, BBC Sport|
Keighley Cougars captain James Feather says the club will change forever after the death of team-mate Danny Jones.
Jones collapsed by the side of the pitch during Sunday's League 1 game at London Skolars.
The Wales international, 29, was later pronounced dead at the Royal Free Hospital. His number six shirt has been retired by the club in tribute.
"It's not going to be the same playing here now," Feather told the BBC's Super League Show.
Jones had complained of "shaky legs" after the warm-up but opted to start the game.
However, he asked to be substituted after four minutes and was in the dug-out when he collapsed.
The London Ambulance Service said it was called to the New River Stadium to reports of a cardiac arrest.
Speaking from Cougar Park, where fans have been paying tribute, Feather said the club would give Jones's wife Lizzie and their five-month-old twins their full support.
Feather, who played alongside Jones for 10 years, said: "I don't know how we're going to go on - it's something we'll have to take a step at a time together.
"It's going to be hard. It's a tragedy."
Following a request from Jones's family, Keighley's home game against Coventry Bears on Sunday will go ahead as planned, with a third of the gate receipts going towards a fundraising campaign that has been set up in the player's honour and has already exceeded £50,000.
Keighley chairman Gary Fawcett told BBC Sport that Jones was not involved in a collision and had not made a tackle before being substituted.
"He went out for the warm-up and said afterwards his legs felt a bit shaky, but rugby players tend to play through things like that," said Fawcett.
"The first real indication we thought something was wrong was after we scored a try. He would normally take the conversion but on this occasion he didn't.
"The next minute he said he felt funny. The physio went over and he asked to come off. He sat in the dugout and collapsed by the side of the pitch."
Fawcett said Jones' team-mates were struggling to come to terms with his death, adding a Rugby Football League welfare officer would speak to them.
Jones, who scored more than 1,000 points in 150 appearances for Keighley and won 12 caps for Wales, was described as "the life and soul in the dressing room, a natural leader, a true professional and irreplaceable" in a club statement.
Wales head coach John Kear told BBC Radio 5 live: "He has two lovely twins and they need supporting now."
Super League players Kyle Amor, Adam Cuthbertson, Tyrone McCarthy and Craig Huby are to shave their hair and beards off to raise money.
A post-mortem examination and inquest into Jones's death will be held at a later date.
Kear was Wakefield Trinity Wildcats coach when forward Adam Watene, 31, died from a cardiac arrest following a training session in 2008.
Six months later Leon Walker, 20 died during a reserve game. It was later found he had a heart defect.