“As the medical process unfolds and information is gathered internally, no other details are being made publicly available at this time,” the statement said.
But Garth Lagerway, the Sounders’ general manager, told the Seattle Times: “Everybody here – us, US Soccer, Clint – we’re all on the same page. Let’s get to the bottom of this, let’s see what’s going on and let’s do what’s best for Clint.”
There is no clear timeline for a more specific diagnosis or a potential return to action.
Dempsey, 33, has scored eight goals this season, including five goals and an assist in the Sounders’ current five-game unbeaten run. He scored two goals in the 3-1 win over Timbers last week before sitting out Seattle’s 1-1 draw with Houston on Wednesday.
Dempsey, formerly of Fulham and Tottenham, has 52 national team goals, and scored three in this summer’s Copa America Centenario.
USA play Saint Vincent & the Grenadines on 2 September and host Trinidad & Tobago four days later. Jürgen Klinsmann’s team sit second in their qualifying group with two wins from four.
The top two from each group qualify for the final round, known as the “Hex”, from which the top three advance directly for the finals in Russia.
This article was written by Guardian sport, for theguardian.com on Friday 26th August 2016 20.47 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010