Successful code hopper Sonny Bill Williams said he expected Benji Marshall to face a tough task in his failed bid to switch to rugby union.
Williams, who is currently playing for the Sydney Roosters in the NRL, returns to rugby next season with the Chiefs.
The former All Black won the Super Rugby title with the Chiefs and a World Cup winner's medal during his previous stint in the 15-man code.
He told Australia's Daily Telegraph that Marshall faced a big ask when he signed with the Blues from Wests Tigers in the NRL, mainly due to the position he was playing.
Williams followed a much different path to Marshall in rugby. He started out with Toulon in the Top 14, where he spent two seasons, before cutting his teeth in the ITM Cup with Canterbury.
He only made his Super Rugby debut with the Crusaders in his third season whereas Marshall was rushed straight into action for the Blues after a handful of pre-season matches.
"When he went to rugby union I thought it was going to be tough for him when I heard he was going try to play No 10," Williams told the Daily Telegraph.
"It's a lot tougher transition to make than being an outside back. A finisher is naturally born for the position.
"You try to beat a couple of blokes and score. Being a decisive player in the team where you have to make quick calls, and step up, lead the team around, that's hard.
"It was sad to see him come back and not go as well as he hoped. Hopefully he gets an NRL team soon and we get to play against him."