Michael Ballack could be a doubtful starter for Germany’s World Cup qualifier against Wales and goalkeeper Petr Cech is a doubt for Czech Republic, meaning Chelsea’s injury list could have further additions ahead of the weekend's Premier League game against Middlesbrough.

Ballack worsened a calf injury in his nation’s 2-1 success over Russia and has been unfit to train. Cech picked up a thigh problem on international duty and will be monitored in view of Czech Republic's World Cup qualifier against Slovenia on Wednesday.

Blues manager Luiz Felipe Scolari will be a worried man after this news as he is already without key players like Deco (thigh), Didier Drogba (knee), Ricardo Carvalho (knee), Michael Essien (knee).

John Terry (back) and Ashley Cole (hamstring) have also been sidelined for England’s qualifier against Belarus while Nicolas Anelka (leg), Alex (hip and thigh), and Joe Cole’s (ankle) availability for the weekend seems uncertain.