The Arsenal right-back is one of the most promising defenders in Europe.
The 21-year-old has emerged as arguably Europe's finest young right-back after breaking into the Arsenal first team in January, 2015.
The jet-heeled Spaniard posted another lively display on Saturday as the Gunners edged out Swansea City 3-2 at the Emirates Stadium.
Fans of the North London club are no stranger to seeing their best young players being lured away from the club, and long before their peak years.
Manchester City and Barcelona have been linked with Bellerin and Arsenal fans might be dreading next summer's transfer window if the youngster maintains this form.
But Cazorla has said that manager Arsene Wenger cannot afford to sell his compatriot, suggesting it would be a mistake if the club loses him.
"We'll see [what happens with Hector]. It is clear that Hector is the right-back of the future," Cazorla told IBTimes UK.
"You could see in the victory over Swansea how good he is. He was all over the place and never stopped running. For Arsenal it would be a mistake to let him go. It is obvious that many teams want him.
"There has been talk about Manchester City and Barcelona. He is a player with great potential and I am sure he will also be a key part of the future of the Spanish national team."
Bellerin only has some two and a half years left on his current contract, and Arsenal will want to extend that as soon as possible.
If they do lose him, they will want to be handsomely compensated, but the less time remaining on his contract effectively lessens his value.