The Dover midfielder leaves for AFC Wimbledon - following a large number of players to make the jump up into the EFL.
The Whites are facing another summer rebuild with Ryan Bird and Manny Parry also leaving this close season.
“I’ve spoken to Jake Lerberl (Dover’s Assistant Manager) about him over the past week to find out more about his character, we’ve had scouts watch him and I went to see him myself,” said Dons coach Simon Bassey.
“He’s a good athlete, tall, he can cover the ground, get around the pitch and he’s versatile. He can play in numerous positions off the right and off the left.
“I’ve even seen him play at left-back, although it’s not his favourite position. We’ve brought a good character into the team to add competition for places.
“He’s got a good background and we’re really pleased to give him a second chance.”
Pinnock has options but told the club’s website about his excitement.
“There were a few other clubs interested, but I felt AFC Wimbledon was the right club for me,” said the midfielder. “They’ve taken players from Non-League before and given them chances, I felt it would be good for me to come here and it’s a club going in the right direction.”