World Cup winner Catt's rewards for an outstanding season with London Irish were the Guinness Premiership player of the season award and an England recall for next month's tour to Australia.
And former All Black Spencer believes 34-year-old Catt is just the sort of experienced old head England need as they hand a number of their established stars a summer rest.
"Good on him. It looked as though he was done and dusted but it's good to see the old fella back for another Test," said Spencer.
"He's had a great season and deserves to be back in. He brings the experience to what is a relatively young England back line."
Spencer, now playing for Northampton Saints, sees Catt as the ideal man to play alongside Newcastle's Mathew Tait, whose confidence suffered after he was substituted - and subsequently dropped - by coach Andy Robinson on his England debut the day before his 19th birthday.
The youngster has bounced back with successful Churchill Cup appearances for England A last summer and a starring role in this year's Commonwealth Games Sevens in Melbourne.
With Catt alongside him, Spencer is convinced Tait, now 20, can establish himself with England second time around.
Kiwi Spencer added: "He's an exciting young player and he'll have old shoulders beside him. That always helps."
The pairing of Catt and Tait sees Bath's Olly Barkley, who has made most of his England appearances in the centre, wearing the number 10 jersey directly opposite Spencer.
But Spencer believes fly-half could well be Barkley's most effective position and added: "Olly's another exciting up and coming player.
"He's a bit of a ball player, which England needs at the moment, so it's great to see him in. He takes the ball to the line more than a lot of fly-halves do over here. I think he'll fit in well there."
The end-of-season game also sees England head coach Robinson's new backroom team of Mike Ford, Brian Ashton and John Wells on duty for the first time.
Spencer said: "They've got something to prove so that will make it tough come Sunday. We're going to attack them and I'm sure they won't disappoint us."