England midfielder Steven Gerrard sat out training with the squad on Wednesday because of the back problem that forced him out of Tuesday's session.
The 26-year-old has a stiff back, but officials are confident he will be fit for Saturday's opener against Paraguay.
An FA spokesman said: "Steven not training is purely precautionary and we expect him to be ready for Saturday."
Gerrard and Wayne Rooney, who has flown back to England for a scan, were the only absentees from the session.
David Beckham, Ashley Cole, John Terry and Gary Neville all continued full training after making their return from niggling injuries on Tuesday.
In stark contrast to Tuesday's session, which was watched by hundreds of German schoolchildren, England enjoyed a private session, with television cameras only allowed into the opening warm-up exercises.
Terry, who caused a slight scare on Tuesday after going down heavily following a challenge from Chelsea teammate Wayne Bridge, looked comfortable as the squad went through a series of stretching exercises.