Cronulla captain Paul Gallen can't see Sharks teammate Valentine Holmes making it in the NFL and suspects his cross-code dalliance is a ploy to bump up his NRL value.
Holmes and North Queensland's 2016 Dally M Medallist Jason Taumalolo will participate in NFL trials in Los Angeles.
The pair flew to the US together from London on Monday after clashing in the Four Nations final between Australia and New Zealand.
Both are committed to their NRL clubs in 2017 and the trials on Saturday are seen as little more than a chance to test their wares and impress NFL scouts with their athletic ability.
Gallen isn't questioning Holmes' talents, but doubts his premiership-winning Sharks teammate could make it after Jarryd Hayne struggled to fully convince the San Francisco 49ers that he could.
"Do I think Val can make it? At this stage no," Gallen said on Triple M's Rush Hour.
"I don't know enough about that game but Val's upper body I don't think will be big enough to play that game.
"He's certainly got big strong legs and he's an unbelievable athlete but I saw what Jarryd Hayne did over there.
"Jarryd Hayne went very well obviously but 'Haynsey' is a much bigger man and much more athletic.
"I think if you give Val another couple of years to fill out and develop and grow as a man, then maybe he could go and do it, but at this stage I couldn't see him making it."
Both Holmes and Taumalolo are believed to be deep into negotiations to remain with their NRL clubs beyond the end of the 2017 season.
"I think it'll be a great opportunity for them but I can't help but think this is a bit of a ploy to say 'look these blokes have options'," Gallen said of the trials midway through the NFL season.
"They both have the same manager and they are both going to be certainly in the top five players off contract next year."