Louis Rees-Zammit says he does not care about the "haters" after being added to the Jacksonville Jaguars' practice squad.
The former Wales rugby union wing failed to make the 53-man NFL roster for the Kansas City Chiefs after training with the Super Bowl champions in pre-season.
The 23-year-old has since joined the Jaguars' practice squad and says he has ignored suggestions Jacksonville's move for him was motivated in part by their London links.
The Jags have played a game in the English capital in 10 straight NFL seasons and have long been linked with a permanent move the London.
This season, which begins on Thursday, they face the Chicago Bears at Tottenham Hotspur Stadium (October 13) before hosting the New England Patriots at Wembley (October 20).
"I don't really care about haters," Rees-Zammit told BBC Sport's Nesta McGregor.
"They can say what they want behind their phones, behind their laptops making comments.
"I don't listen to that kind of stuff. I know what I've got to do to be successful and they can write all they want.
"I'm working really hard on this dream and I've got to try and do as much as I can every day to be a better football player and a better person."
Jacksonville were one of several franchises that showed interest in Rees-Zammit after his impressive showing in the International Player Pathway (IPP) pro day in March before he signed for the Chiefs.
Rees-Zammit signed a three-year deal with the Chiefs before playing three pre-season games, including a debut against the Florida-based Jaguars, after successfully coming through the NFL's IPP program.
He missed out on their 'cutdown day' selection but still harbours ambitions of playing in the league after switching to the Jaguars.
Each NFL team can have one international player on its practice squad alongside 16 other players.
Practice squad players can work out during the week with NFL teams but are ineligible to play in actual games unless the player is elevated to the regular roster.
"It would mean everything playing in the NFL," said Rees-Zammit.
"I've played pre-season games, but to play a regular season game would be unbelievable.
"That was the first time I've ever played football so to get on to a 53 that soon was very unlikely.
"But you've got to stay level-headed and I'm so thankful to this team for giving me the opportunity to be able to carry on my dream.
"It's a team with a very bright future with some very exciting players and coaches, so I'm very happy."