Real Betis goalkeeper Toni Doblas has been ruled out of action for around six weeks with thrombosis of a vein in his right arm.
The 26-year-old's arm swelled up during a training session on Monday leading the club to hurriedly send him for tests.
Medics decided the complaint was caused either by a problem in circulation or by the player overexerting in the gym.
Doblas now faces an extended period on the sidelines and has been ordered to give the arm complete rest.
"It's a strange injury that could be down to a trauma in the arm or by me overdoing it, because I often lift a lot of weights," Doblas explained.
"Yesterday when I was training the arm suddenly swelled up and the veins started jumping out."
Doblas started the season as Betis number one but has been displaced by Pedro Contreras in recent weeks.