Cabanas still in critical condition
The 29-year-old, a prolific goal-scorer who was expected to lead the Paraguay attack at the World Cup in June, was shot at a Mexico City bar just before dawn on Monday.
Police are investigating whether Cabanas was involved in a dispute that carried into the bathroom where he was gunned down.
Swelling has complicated the outlook for Cabanas, who still has a bullet lodged in his brain, surgeon Ernesto Martinez told reporters.
"We have to wait a little more because he is still in grave condition and has not passed the point of serious risk to his life," Martinez said.
"We knew this would happen. The most probable outcome is the swelling continues to worsen."
Doctors said they would make a more complete prognosis on Thursday.
Cabanas plays for Mexican club America and was Paraguay's top-scorer in the qualifying competition for the World Cup in South Africa, with six goals.