Cipriani has not played for England since 29 November
Wasps head coach Shaun Edwards insists Danny Cipriani will be back to his very best next season after the fly-half was left out of the Lions squad.
Cipriani did not feature in the Six Nations following a poor autumn series after his return from ankle surgery.
"I'm sure next season Danny will be back to his absolute premium," Lions defence coach Edwards told BBC Sport.
"Danny has shown incredible mental and physical toughness to be playing with a four-inch screw in his ankle."
Cipriani, 22, suffered a fracture dislocation of his right ankle last May, but returned to action quicker than expected in October.
He was selected to start the first three autumn Tests before being relegated to the bench against New Zealand, his last England outing.
He has failed to rediscover the kind of form that saw him named man-of-the-match against Ireland last March and failed to even make the bench for the Six Nations.
But Edwards believes he will rediscover his best form once the screw is removed from his ankle this summer.
"I remember Lawrence Dallaglio having a similar injury (in June 2005) and battling through the season with sheer grit and determination," Edwards said.
"Danny has shown exactly the same. When Lawrence had the screw removed the following summer, he had a spring back in his step."
Ian McGeechan, who is also director of rugby at Wasps, overlooked Cipriani for the Lions tour.
Attack coach Rob Howley explained why McGeechan had opted to take only two specialist fly-halves, Stephen Jones and Ronan O'Gara.
"We wanted to go with three 10s, but unfortunately we were disappointed that a third didn't put his hand up," he said.
A lack of England games destroyed Cipriani's Lions chances
"We watched James Hook and Danny Cipriani, and Sam Vesty has been mentioned.
"We discussed whether to take another 10 who didn't necessarily deserve that opportunity or whether to take another player. We went for the second option."
Edwards admitted it was difficult to argue for Cipriani's inclusion in the Lions squad when he had not been playing for his country.
"Danny was one of the fly-halves or utility backs we discussed," he said.
"It obviously helps if you're number one in your country in your position, which Danny wasn't during the Six Nations. I'm convinced Danny's time will come."