Chelsea boss Graham Potter admits every player with World Cup aspirations is in "a tricky position" as domestic football continues just days before teams fly to Qatar.
The Blues are waiting on news of Ben Chilwell's hamstring injury, as he headed for a scan on Friday amid fears the muscle is torn, which would rule him out of England's plans.
Potter understands players have concerns about suffering injuries at such an unfortunate moment, but will demand his squad hold nothing back in Sunday's Premier League meeting with Arsenal.
Chelsea striker Pierre-Emerick Aubameyang is poised to face his former club, and unlike many of his team-mates does not need to worry about the World Cup, which starts on November 20, having retired from international football within months of Gabon failing to qualify.
Asked about possible fear of World Cup hopefuls getting hurt, Potter said in a press conference: "I don't think it's fear. I just think it's part of the challenge.
"It's very difficult to play Premier League football or Champions League football and go at it half-hearted. That's pretty much impossible. At the same time, there's a World Cup a couple of weeks away, so it's a tricky position for everybody."
Chelsea needed to wait for swelling to reduce before sending left-back Chilwell to be assessed, and Potter did not sound positive about the defender's England prospects.
"We all saw the nature of the injury," Potter said. "I can't say it looks positive, but until we get the scan it's difficult to say. At the moment we're just hopeful and fingers crossed, and from there we see how to get him back fit and strong. It's disappointing, of course."
Aubameyang's exit from Arsenal in February, when he moved to Barcelona, came after an apparent falling-out with head coach Mikel Arteta, as the former Gunners captain lost his first-team place.
After a short stint at Barcelona, Chelsea jumped at the chance to bring Aubameyang back to England, and Potter concurred it would be "an interesting one" for the 33-year-old this weekend.
"I don't think we should make it about him," he added. "I think it's about the team. He's an important part of the team and for us to get the result we want takes everybody, not just one person.
"I understand the interest is about him because it's Arsenal and there's a narrative about that. But as a team and a group we have to do well ourselves."
As for whether Aubameyang has anything to prove to Arsenal, for whom he scored 92 goals across all competitions, Potter suggested not.
"I don't think so. I think he's looking forward to the game, excited for it," Potter said. "He's been pretty normal from what I've seen, he's quite a quiet guy, but I'm sure come matchday he'll be determined."
Potter praised Arsenal's support for Arteta, who came under pressure in the early stages of his tenure, describing the backing the Spaniard has received as "a really good example of how success can come".
Former Brighton and Hove Albion boss Potter is still learning the ropes at Chelsea, but he had success against Arsenal during his time with the Seagulls, winning three of his six Premier League games against the Gunners (D1 L2).
Chelsea will hope that boosts their prospects, given they have lost three of their last four league games against Arsenal, more defeats than they had experienced in their previous 17 in the rivalry.
Moreover, Arsenal have won on their last two league visits to Stamford Bridge, as many victories as they achieved in their previous 16 visits.
League leaders Arsenal have not won three in a row at Stamford Bridge since April 1974, but that could change on Sunday.