Novak Djokovic has entered the ATP event in Adelaide the week before the Australian Open.
Adelaide's Advertiser newspaper said it had confirmed that Djokovic was among the names in the field before yesterday's cutoff, though there was initially no announcement from the event.
Djokovic is already signed up to play the Abu Dhabi exhibition event during the offseason, two weeks before the start of the 10-day ATP Cup.
The No.2 could have entered the event to give himself an opportunity for extra match play if the Serbian team does not go deep at the ATP Cup, though the round-robin event guarantees three ties for each nation.
However, withdrawals are common for events played the week before a Grand Slam.
It will be the first year for the event in Adelaide, which has moved from its previous location in Sydney.
The next-highest ranked player in the field is Australian and No. 18 Alex de Minaur.