The Netherlands and Liverpool must wait to discover the extent of an ankle injury suffered by forward Cody Gakpo on Sunday.
Gakpo lasted just 17 minutes of the Netherlands' 2-1 UEFA Nations League win in Serbia before having to be substituted as a result of a hard tackle minutes earlier.
"It's his ankle, that's all I know," Netherlands boss Xavi Hernández said. "Tomorrow we will know, but hopefully it's not too important."
Gakpo had scored in the Netherlands' 1-1 draw with Germany on Thursday in what was Xavi's first match in charge. The Dutch will next visit Greece on Thursday before hosting Serbia on Oct. 4.
The news will be of particular concern to Liverpool, after the revelation earlier on Sunday that another forward, Alexander Isak, was set to return to the club after suffering an injury while on international duty with Sweden.
A statement on Liverpool's website read: "Alexander Isak is to return to Liverpool from international duty due to a minor injury.
"The striker will not be involved in Sweden's three remaining fixtures in the current international break and will now be assessed by club medical staff at the AXA Training Centre."
Both Gakpo and Isak have made strong starts to the season and Liverpool will hope to have both of them fit for their next Premier League game against Manchester City on Oct. 11.
