Otto suffered a knee injury during Spain's 1-0 friendly win over Bosnia at the weekend.

After undergoing tests on Monday morning it's been confirmed that the 24-year-old has a partial ligament tear in his right knee.

A statement today said: "(Otto) suffered a partial tear of the internal lateral ligament of his knee, that has been detected in the tests carried out on the morning of this Monday.

"It is estimated an absence of five or six weeks."

If sidelined for six weeks, the Spaniard would miss almost a quarter of Wolves' league campaign with eight matches scheduled for between now and the end of the calendar year.

Wolves are also sweating on the fitness of fellow wing-back Matt Doherty who suffered a blow to the face towards the end of the 1-1 draw at Arsenal.

Doherty dropped out of the Ireland squad and it's not yet known if he will be fit to face Huddersfield Town at Molineux on Sunday.