It is understood the problem is not too serious, but England's medical staff will manage the Liverpool captain's fitness carefully ahead of Wednesday's match.
"It's a special feeling to know that people back home and out here in Russian Federation are enjoying the experience just as much as we are", the midfielder said on the eve of the game.
"We'll just have to assess people as we go".More news: Paul Manafort treated like a 'VIP' in prison, court documents show
She said: "We had a brilliant day there". We win as a team. The biggest thing for me is just continuing to win - and hopefully a few more wins over the next week'.
"That's what I have a focus on".
Henderson has started four of England's five 2018 World Cup games, as he was rested in the group-stage fixture against Belgium. We'll do our best to try keep him quiet, but everybody else as well, because they have a lot of threats from different areas.
The teacher said: "They have been having Pickford and Henderson days in school".More news: Cornwall woman takes vehicle for accidental, two-week joyride
"I think he's had his fair share of criticism over the past year or so, but he's done so well over the last six months, really, especially after the start of the season".
"But he is not only a workhorse, he is a really good footballer as well so I am happy for him that he is getting a little bit of the light and it is well deserved".
Pickford came to prominence in June 2017 when Everton paid Sunderland £30m for him.
France await the winners of tonight's semi final.More news: Russell Knox uses incredible clutch putting to win Irish Open in playoff
- Theresa May presses on with Brexit plan after high-profile resignations
- Denies Having a 360 Deal with Atlantic, Countersues 'Controlling' Ex-Manager
- Kepler Spacecraft’s Fuel Tank is Running Very Low
- Bluster aside, US and China vulnerable to pain from tariffs
- UCLA's Billy Knight Allegedly Sexually Abused 9-Year-Old Girl Before Death
- Croatia vs. England, Semifinals
- Roger Federer loses five-set match to Kevin Anderson
- England nowhere near their potential, says manager Gareth Southgate
- Trump administration threatens tariffs on another $200 billion in Chinese imports
- Harold Varner III tied for lead at the Greenbriar