Lionel Messi touched down in California on Friday as Argentina prepared for the possibility that the injured Barcelona superstar may not be fit for next week's Copa America Centenario showdown with Chile.

Messi arrived in the early hours from Barcelona, where on Thursday he had appeared in court to give evidence in his tax fraud trial which has also embroiled his father.

Messi, who suffered a back injury in a friendly victory against Honduras last week, is uncertain to be fit for Monday's crucial Group D game against Chile at the Levi's Stadium in Santa Clara.

The 28-year-old playmaker later took to the field during training near Argentina's San Jose base. Messi trained separately from the rest of the squad along with another injured player Lucas Biglia.

Meanwhile teammates Augusto Fernandez and Nahuel Guzman admitted Friday that Argentina were facing up to the possibility of Messi's absence against the Chileans.

"It is logical that being the best player in the world it is clear that we all want him to be fit," Atletico Madrid midfielder Fernandez said, adding that he was confident the squad would cope against the Chileans if Messi was ruled out.