Nonu, selected for the All Blacks at both wing and centre, returns to rugby after a seven-week injury hiatus due to a broken thumb, which will be protected if he plays.
Lions backs coach Chris Boyd told The Dominion Post "He's got a guard to play with, he's been cleared by the medical team to train and he will undergo a fitness test."
Hurricanes winger Hosea Gear (hamstring) and Tamati Ellison will also receive late tests.
Nonu and Conrad Smith, who has also returned to the Lions team after a long-standing injury, are possible contenders to replace team-mate Tana Umaga as New Zealand's outside centre.
