The Spaniard damaged his ankle ligaments against QPR ten days ago, but the Swans were hopeful he would recover in time for the showpiece clash at Wembley.
In a bid to fast-track the 25-year-old’s return to full fitness, the club have been giving him round-the-clock treatment, but it appears to be unlikely that this will be enough.
Manager Michael Laudrup has set Chico a deadline of Thursday to prove his fitness for the club’s first major final, a game he will be desperate to feature in.
If the man who arrived from Genoa over the summer cannot recover in time, one of Kyle Bartley or Garry Monk will partner Ashley Williams at the heart of the Welsh side’s defence.
The duo featured in Swansea’s 5-0 defeat at the hands of Liverpool last weekend, as Laudrup shuffled his pack in a bid to keep his star players fresh.
The Dane will be hopeful that the heavy loss would not have dented Monk or Bartley’s confidence ahead of, arguably, the biggest game in the club’s history.
Meanwhile, South Korean midfielder Ki Sung-Yueng is in line to return to the first-team squad, after missing the Anfield trip with a throat infection.