"I heard someone say if it was 85 minutes we would have nine points by now," Moyes told British media.
"I wish we were if that was the case, but I think it is more to do with us not having the ball enough and, by the end of the game, it wears you down.
"Your fitness levels can go and your concentration can go and I would say that is probably what it is down to, more than anything else ... I think we have shown slight signs of getting better.
"We have to try and keep that up, and keep this little bit of positivity up. But obviously we don't want to keep getting beat, that is for sure."
Sunderland travel to face Southampton in the fourth round of the League Cup on Wednesday before hosting second-placed Arsenal in the league three day later.
(Reporting by Shravanth Vijayakumar in Bengaluru; Editing by Peter Rutherford)
