Newcastle have lost of 10 of the 15 Premier League matches they have played this year, and have lost each of their last four matches without scoring.
This run has ended their hopes of challenging for a European qualification spot, leaving them ninth in the table and 20 points behind fifth-placed Everton.
There has been recent discontent amongst the United fans, some of whom held aloft banners during last weekend's 1-0 defeat at Stoke last weekend asking for manager Alan Pardew to be sacked.
And Santon is sympathetic to the supporters' dissatisfaction.
"I think it is normal when you play five games and lose four, 3-0, 4-0, 4-0 and you never score," said the 23-year-old Italian defender.
"Of course it is going to be frustrating for them, especially when we play away and they come and spend a lot of money."
Santon has had missed much of this season and will not play again in the campaign due to a recurring hamstring injury.
"I was feeling better and getting quicker but the Thursday before the Stoke game, in training, I jumped and felt my hamstring again.
"It is really frustrating but that is football. I have to accept it, work hard and be back as soon as possible."