Alexis Sanchez is in doubt for Chile's World Cup qualifier against Brazil on Thursday.

The Arsenal star is battling the groin problem he picked up in Sunday's 3-0 win over Manchester United and may not be fit in time to face the Brazilians in their Russia 2018 qualifying opener in Santiago.

Chile boss Jorge Sampaoli revealed that Alexis was struggling, along with star midfielder Arturo Vidal: "Neither Vidal nor Alexis are confirmed for the Brazil game."

The pair could be back in action for Tuesday's trip to Lima to take on Peru.