Great Britain's Kyle Edmund has pulled out of this week's Argentina Open because of a throat infection.
The 23-year-old British number two was due to play in Buenos Aires in his first competition since reaching the semi-finals of the Australian Open.
The world number 26 had been scheduled to face Spain's Roberto Carballes Baena in the first round on Tuesday.
Edmund, who did not play in Britain's Davis Cup loss to Spain, is expected to be fit for next week's Rio Open.
A run to the final would mean Edmund would overtake Andy Murray to become British number one for the first time.
However, that change will happen on 5 March anyway after Murray's points for winning last year's Dubai Championships come off as the Scot, who has not played a competitive match since last year's Wimbledon, remains sidelined with a hip injury.