Nygren was taken off after 64 minutes of Sweden’s 2-2 draw with Greece, a moment that briefly threatened to cloud the build-up to Monday’s game in Monterrey. But his own description of the incident sounded far more reassuring than alarming.
"I passed, then he came in and tackled me so I twisted my ankle," Nygren said. He then added: "It hurt right then and there. We were going to change anyway so we took it safe before it was too late."
That matters for Sweden. Nygren has become the kind of forward who can play across the line, stretch a defence and give his side a direct threat when matches tighten up. Even if he is not at full throttle, his availability would still be a lift.
If the ankle scare looks manageable, the transfer chatter is not. Nygren’s first season at Celtic put him firmly in the spotlight, with 21 goals in 58 appearances in all competitions after arriving from Nordsjaelland for £1.3m. He finished the campaign as the Scottish champions’ leading scorer and looks like a player whose stock has risen quickly.
Reports have linked Tottenham Hotspur with the 25-year-old, and Nygren’s "We’ll see what happens" did little to quieten the noise. It was not a declaration, but it was hardly a shutdown either.
For both player and country, the timing is awkward but familiar. Big tournaments often sharpen transfer speculation, especially around attackers coming off a breakthrough season. A strong display against Tunisia would only intensify that conversation.
First, though, Sweden need Nygren fit enough to take the field. If he makes it through Monday, the next storyline will be obvious: how far he can take Sweden in the tournament - and whether this summer becomes about more than just the World Cup.