Beckham, 37, left on his 16,500km round-trip last Wednesday before returning to Paris on Monday, visiting three Chinese cities as part of a long-planned ambassadorial role.
Ancelotti has included the veteran midfielder in the squad for Ligue 1 leaders PSG's home clash against Montpellier on Friday despite some fears that he may not be fit enough to feature for the full 90 minutes.
"If he were to come on with five minutes left in the match, then that would be manageable. If it was for an hour and a half, then that would not be reasonable," club doctor Dominique Savelli told AFP.
"It all depends on how well he sleeps. He is used to travelling. But these are not optimal conditions, flying for five days with a time difference. You are not in the shape that you would be if you were sleeping for the normal amount in your own bed."
But Ancelotti said he had no concerns over Beckham's fitness and would also be happy to see the former Manchester United and Real Madrid star remain at the club beyond his current deal which expires at the end of the season.
"I would be totally in agreement if Beckham prolongs his contract," said the Italian.
On the player's trip to China, where he also took part in three training sessions, Ancelotti said he was mystified why the visit had sparked so much discussion.
"It was an agreement that he made before his contract with PSG, everyone agreed. There was no problem for me, I also agreed," said Ancelotti.
"The players that remained in Paris during the international break had three days off; Beckham had four. He missed just one training session, that's all. He could perhaps start the game against Montpellier."