Cobblers boss Keith Curle felt John-Joe O'Toole's summer move to Burton Albion was best for all involved ahead of Sunday's reunion in the FA Cup third-round.
The 31-year-old held discussions with Curle towards the end of last season but, despite being offered a contract, he opted to part ways after five years at the club.
O'Toole later signed a two-year contract with League One Burton and has been a regular for Nigel Clough's team this season, making 25 appearances so far.
"I think it was a move that suited both parties," said Curle. "John-Joe had decided he wanted a new challenge and the time was right for him to accept that new challenge, which was excellent for the lad.
"He went up a division and tested himself at another level and at another football club.
"At the time we weren't able to match League One wages, which is no disgrace, but I think we left on good terms.
"I enjoyed working with John-Joe but I think he understood where I was coming from and I sensed he needed a new challenge as well and I think that was the agreement we had between us.
"He's got some fantastic memories of this club and he was an integral part of the success here and he left with his held high."
O'Toole was banned for six games after being sent off against Southend last month but he's free to face the Cobblers on Sunday and Curle's looking forward to meeting up with his former midfielder.
"He's been suspended for a few weeks so he'll be disappointed with that and they've picked up a couple of results recently," Curle added.
"I'm sure not sure if he'll back in the starting line-up but he'll be champing at the bit to play against Northampton Town, I know that."