The former Chelsea stopper wrote in the London Evening Standard: "I can certainly see German clubs outperforming English ones in the Champions League this season. Dortmund have been superb in the competition and they can certainly go further, while the game between Schalke and Galatasaray looks an even one.
"We've discussed how difficult it will be for Arsenal and Manchester United have their work cut out, too, to knock out Real Madrid at this stage. I hope Hamburg can be involved next year. We're sixth in the table and I hope I can recover from this ankle injury in time to help us push for a top-four finish over the rest of the season.
"I've been out since mid-January and, while I'm now back on the treadmill, I've still not been able to join in full training sessions with my team-mates."