Gardner has enjoyed a successful loan spell at Nottingham Forest, but Sherwood will welcome Gardner back into his first team squad during pre-season to assess closely whether the 22-year-old can cut it for Aston Villa in the Premier League.
"I will go back to Villa in the summer and we will see what happens," he said. "When I am back there in training, it will be my chance to impress. Tim Sherwood will not have seen much of me in training, because I have not been there.
"Villa are the main club, I have been there since I was seven and it is the team I support. But Forest have been fantastic to me. It is definitely the second team in my heart.
"If I was made available for loan again next season, if it does not work out at Villa, Forest would be top of my list, definitely. It is the best loan move I have had."