The Blues are looking to Spain's second tier for talent it seems.
Birmingham City are keen on two Spanish-based stars, the Sun reports (Thursday edition, page 55).
The Blues, who finished 10th in last season's Championship, have added four new faces so far, though three of those, James Vaughan, Ryan Shotton and Robert Tesche, were previously on loan at St. Andrew's.
Villar, who plays for Real Valladolid, was a rumoured target for Brighton & Hove Albion, Derby County, Queens Park Rangers and Reading earlier this year.
The 28-year-old, a natural right winger who can also play up front, scored 15 league goals last season.
Cabrera, meanwhile, is currently on the books of Real Zaragoza, having previously played for Atletico Madrid.
The 25-year-old, a former under-20 international for Uruguay, can operate in both centre-back and left-back roles.
Gary Rowett's side have lost a string of stars over the course of the summer, including loanees Jon Toral, Will Buckley and Kyle Lafferty.
They begin the new campaign at home to Cardiff City in nine days time.