The Scot's 25-man Premier League squad list is almost complete.
But while the Norwich boss would welcome another addition ahead of the August 31 transfer deadline, probably in defence, Lambert stressed: "I won't just buy someone for the sake of bringing them in.
"I am delighted with the squad that's here at the minute, if you can improve you try and do it.
"I've got six in, which is roughly the number I said we'd need, there might be room for manoeuvre somewhere along the line, but I am delighted with the group."
Lambert - who maintained ties with Germany from his time at Borussia Dortmund, where he won the 1997 Champions League - feels the trip away can help the squad bond.
"We will train as hard as we can, get everybody fit and get everybody gelling together," he said.