It will be a three-way fight for the No 9 jersey, with Charlie Shiel also in the mix. Shiel, the youngest of the three scrum-halves, also signed a new deal yesterday.
It means a likely departure for Nic Groom, with the experienced South African expected to leave the club in the summer.
Pyrgos, who joined Edinburgh from Glasgow in 2018, said it was not a difficult decision to extend his stay in the capital.
“I’ve really enjoyed my time at Edinburgh so far,” he said. “I just moved to the city before lockdown so it has been a pretty enjoyable three years so far.”
The arrival of former Scotland under-20 scrum-half Vellacott will spice up the competition but it’s something the experienced Pyrgos is ready for.
“Ben looks like a really good player so it will be great for the squad. He’ll add an extra dimension and more competition for that nine jersey. So, it will be good for the club and definitely a challenge for those of us at the club already.”
At 31, Pyrgos is the elder Edinburgh statesman at scrum-half. Capped 28 times by Scotland, he has bags of experience and is happy to share it with Shiel and Vellacott.
“Charlie’s playing really well. He’s obviously got a lot of ability and a big future ahead of him, which is great for the club,” said Pyrgos.
“We, as a nines group, are quite supportive of each other – we work hard day-in and day-out, and try to help each other where we can.
“Like any of the young guys, they don’t necessarily need anything from me, but if they do then I’m always ready to help out where I can.
“Charlie has got a great skill-set, so definitely playing really well, and that’s a challenge for myself and great for the club moving forward.”
Edinburgh coach Richard Cockerill said: “Henry and Charlie are both important players for this club and each bring a different style and skillset to the position.
“With Ben Vellacott joining the club next season, we’re really excited to see this group of scrum-halves compete and push each other on.”