Sjeng Schalken is doubtful for his Wimbledon quarter-final clash with Roger Federer after suffering a recurrence of a long-standing foot injury.
Schalken was hampered by the problem during his straight-sets win over Rainer Schuettler on Monday.
And the injury flared up overnight to jeopardise the Dutchman's hopes of reaching the semi-finals for the first time in his career.
He will have an MRI scan on Tuesday evening to determine whether he has a broken bone in his foot.
"I only slept for five or six hours last night because of the pain," said Schalken.
"But I am determined to show up and I only won't play if I am in plaster."
Federer also has injury concerns after pulling a back muscle during the warm-up before his straight-sets win over Feliciano Lopez.
The Swiss fourth seed admitted that he played through the pain and is expected to have intensive physiotherapy on Tuesday.