A report said Ritchie was sparring in Melbourne with Michael Zerefa, who is preparing for a rematch with Jeff Horn, a former WBO welterweight champion.
Day had brain surgery after being knocked out in the 10th round on Saturday night at Wintrust Arena. Knocked down twice earlier in the bout, the junior middleweight was taken from the ring on a stretcher.
Vikas Krishan made it to the next round in the 75kg middle weight category after defeating Charles Conwell at the boxing event at Rio Olympics on Tuesday.
Vikas Krishan (75kg) gave a perfect start to India's boxing campaign in the Rio Olympics 2016, beating Charles Conwell to enter the pre-quarterfinals
A tough draw will put their grit to test when India begins its Olympic campaign, aiming to lift the gloom that pervades the sport back home owing to the long-standing administrative mess.