Bellingham, who plays for Real Madrid at club level, has divided opinion in recent months, with his on-pitch intensity and emotional displays frequently analysed by pundits and supporters. But Henderson said the criticism overlooks the midfielder's true value to the squad.
"I honestly couldn't speak highly enough of him," Henderson told reporters after England training. "A lot gets written in the media, and I find it hard to read sometimes because I know how big an influence he is on this team, how good a teammate he is off the field, and what he gives us is something really special."
Henderson added that Bellingham brings a decisive edge in major moments. "He really gives us the X-factor. He's had big moments in his career, he's a big-game player. He's got experience in tournaments already, so he's a huge player for us."
He also stressed the midfielder's professionalism behind the scenes. "If you ask any player in the group, they'll tell you how good a teammate he is, how well he trains. He's very mature in his head."
England, managed by Thomas Tuchel, open their campaign against Croatia on Wednesday in Dallas. Tuchel's squad selection has sparked debate, with Henderson included ahead of younger midfield options such as Phil Foden, Cole Palmer, Morgan Gibbs-White and Adam Wharton.
Henderson, who returns to a major tournament setup after missing previous international selection periods, said Tuchel had simply asked him to stay himself within the group. "To be myself, regardless of how much I'm playing, whether I'm starting or not, just enjoy being back with the squad."
He also highlighted the challenge posed by Croatia captain Luka Modrić, who is preparing for another World Cup appearance at the age of 40.
"His career speaks for itself. He's world-class. I haven't seen him have a bad game," Henderson said. "It will be a difficult test for whoever plays in midfield."
England's Group F campaign also includes matches against Ghana and Panama as they aim to start strongly in Texas.
AC Milan's rebuild appears set to extend beyond the dugout, with Eintracht Frankfurt sporting director Markus Krosche reportedly agreeing to join the Serie A giants as part of a major restructuring project at San Siro.
Mamelodi Sundowns winger Thapelo Maseko believes Bafana Bafana must raise their intensity if they want to progress to the FIFA World Cup 2026 knockout stage.
Manchester City are on the verge of securing defender Josko Gvardiol, with the Croatian international nearing an agreement on a fresh contract that would keep him at the club until 2031.
Nestory Irankunda has admitted he was still struggling to take in the moment after helping Australia begin their 2026 FIFA World Cup campaign with a stunning 2-0 victory over Turkey.
