Gakpo and Isak set off alarm bells at Liverpool after injuries on international duty

The international break was supposed to be a routine stretch for Liverpool's attack. Then, within a matter of hours, it turned into a double headache back at Anfield.

It started with Cody Gakpo. The Dutchman had barely been on the field for 17 minutes in Sunday's Nations League match against Serbia when he had to come off after a hard challenge. The final score went in the Netherlands' favor, 2-1, but the result was overshadowed by concern over his ankle.

The exact severity of the injury is not yet known. The Dutch head coach was cautious when asked about it.

It's the ankle, that's all I know. We'll find out more tomorrow, but I hope it's nothing serious.Xavi Hernandez

What makes it worse is that Gakpo had been in good form. Just the previous Thursday he scored in a 1-1 draw against Germany, a match that also marked Xavi Hernandez's debut in charge of the national team. Now everything hinges on a diagnosis, one that's expected before the Netherlands travel to Greece next Thursday and then host Serbia on October 4.

Isak, another scare on the same day

As if that weren't enough, Liverpool got another unwelcome update that same Sunday: Alexander Isak will return to the club early after picking up an injury while on duty with Sweden. Liverpool confirmed the news in a statement on its website.

The club statement explained that the forward will be unavailable for Sweden's remaining three matches in this international window, and that he will be assessed directly by the club's medical staff at the AXA Training Centre. It's being described as a "minor" issue, though nobody at Liverpool is taking anything for granted until the scans come back.

The truth is both Gakpo and Isak had been enjoying a strong start to the season, and that's exactly what makes this so worrying at Anfield. Losing either one, even for a short spell, would sting. The goal now is to have both available for a tough test: Manchester City's visit on October 11 in the Premier League. There's still time for things to work out, but the club knows the next few hours, once the medical reports are in, will be crucial.