The Newcastle United goalkeeper is out for at least six weeks due to a heel injury.
Dubravka has had surgery on the injury, which he suffered on a run in his native Slovakia.
"During the penultimate run in Slovakia before leaving for preparation for England when I was fulfilling the set individual plan, I injured my ankle,” Dubravka told sport.sk. “I felt a sting or a half-rupture, respectively. I immediately informed the coaches in Newcastle. After arriving in England, I still trained, despite the pain, but after three days I had to stop.
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"A scan revealed damage to the ligaments, and I've already had a small operation in Leeds. Immediately after it, I boarded a plane and went back home to Zilina. I will rehabilitate here for two weeks, and then I’ll go to England again."