Blues co-sporting directors Paul Winstanley and Laurence Stewart have managed to offload 47 players from across the first-team and Development Squad.
"I am surprised so many experienced players left," said Zola to The Times. "My understanding is they are planning to build a team within the next three or four years but players left that were there a long time and that won a lot – [Cesar] Azpilicueta, Jorginho, [Kai] Havertz, [Mateo] Kovacic — players that probably everyone looked up to.
"You need those players. In difficult moments you rely on those players. So many left and that doesn't help the situation.
"I remember when I was coach at Watford, six or seven new players came on the last day of the market and all of a sudden I had 35 players training — 35!" said the Italian. "We couldn't train them all together so we had to have two separate sessions every day, one from 10 until 12 and another from 12 until 2.
"It was draining for us as coaches and for the players as well. The dynamics of a football team are very particular — who plays where, who is better, who plays well with who, who is loud, who is quiet. All of this takes time. I assume Pochettino knew what he was dealing with at Chelsea and he knows what he wants to do to make it work."