USMNT left back John Tolkin suffers potentially serious knee injury

U.S. men's national team left back John Tolkin suffered a potentially serious knee injury in Holstein Kiel's 2-1 victory against Fortuna Düsseldorf on Friday, April 10.

Only seven minutes into the match, Tolkin went down after appearing to twist his knee awkwardly. After receiving treatment, the 23-year-old limped off the pitch toward the tunnel.

While Die Störche earned a three crucial points at Merkur Spiel-Arena, manager Tim Walter expressed fears of the extent of Tolkin's injury.

"The scene looked really bad," the German manager said. "He is a great footballer and also a kind-hearted person.

"The injury particularly hurts me. I have been very close to John in my heart in recent weeks."

While the injury is a huge blow for Kiel, which is trying to avoid relegation from the 2. Bundesliga, it is for Tolkin as well.

The New York Red Bulls academy product, who last featured for the USMNT in a 5-1 win over Uruguay in November, was fighting for a World Cup roster spot with the tournament commencing in two months.

Tolkin's injury comes four days after Derby County striker Patrick Agyemang suffered an Achilles injury that ruled him out for the World Cup.