Saints beat Leicester Tigers 31-12 in their opening match of this season’s PRC before narrowly overcoming a fired-up Nottingham side 31-29.
“For Nottingham it was their European Cup final, it was their Prem final, you could see how serious they took it,” said Radford.
“They got together in a huddle, you could see there was real intent, it was a really big occasion for them playing at the Premiership champions.”
Northampton, the 2019 Cup winners, complete the first half of the pool stage – return games take place in February – with a trip to Championship and group leaders Coventry on Saturday.
And, like Nottingham, Radford expects they will provide a stern challenge.
“Coventry have got the champions coming to their home ground, they’re going to be after it and the key for us is making sure we turn up with the right energy and intent,” he added.
“We can make errors, we can be a little bit giddy defensively but we can’t lose the energy battle. It’s really important that we dictate the intensity of the game and not let it be dictated to us.”
