The lanky paceman, who retired after helping Australia win the World Cup in West Indies this year, said he had still not signed a deal but was seriously considering an offer.
"It's tempting," McGrath told reporters in Australia.
"Obviously, you can make a little bit of money. Probably a month of cricket, get back, give me that fix of playing again - it might be all I need."
Former West Indies captain Brian Lara has already agreed to play in the competition but organisers have struggled to snare the signatures of many current international players after threats from their national bodies to ban them.
Former Australian batsman Dean Jones, who has been with the organisers to entice big-name players to the competition, would not discuss individual signings but said he was confident the series would go ahead as planned.
"The fans and the viewers will be quite happy with the signings we'll get, trust me," Jones told reporters in Australia on Tuesday.