Curle discusses Cornell's exit and gives update on injured McWilliams
The 29-year-old Welshman made 109 appearances for the Cobblers, 38 of which came during the 2019/20 campaign, but he lost the number one spot to Steve Arnold shortly before lockdown.
Arnold was also selected for the three play-off games as Town won promotion to Sky Bet League One, and therefore confirmation of Cornell's departure on Thursday came as no great shock.
"Without going into the details, in my opinion, Dai needed a new challenge," said Curle. "That's a conversation I had with him and fair play to him because a lot of things we spoke about, he agreed with.
"Potentially, Dai could go and play at a higher level and compete at a higher level but I think the timing was right for him as an individual to go and test himself in new surroundings."
Meanwhile, homegrown midfielder Shaun McWilliams has this week signed a new contract at the club.
The 21-year-old, who made an excellent start to last season, is on the mend following a serious knee injury sustained against Crawley Town last Christmas, and Curle believes he will have an important part to play in the club's League One campaign.
He said: "Shaun's in the final stages of his rehabilitation and hopefully, by the time we get to the first game of next season, he won't be far away from the Shaun McWilliams that everybody in this ground knows.
"Hopefully he'll be ready and he will have done enough training to get himself back in contention for the team. Shaun is the type of player that we're going to need next season because we need to get the ball off the opposition and we need to be a team that goes hunting for the ball.
"We're not going to sit off teams and I think that was evident in the way that we went about the last couple of games in the play-offs."