In further suspension-induced changes up front, hooker James Buckland makes his first start for Tigers, replacing George Chuter, who was suspended for eight weeks for recklessly stamping to the head of a Bath player.
"The absence of any players, be it through injury or any other means, is always going to be a problem, but we have to deal with it," said Wells on Wednesday.
Twenty-three-year-old Buckland, who has come off the bench on three occasions this season, will have Graham Rowntree at loosehead prop and Darren Morris on the other side, with England strongman Julian White getting a well-deserved break on the bench.
In the backline, Harry Ellis returns for Scott Bemand at scrum-half, where he is reunited with Andy Goode at halfback, whilst the fit-again duo of Daryl Gibson and Austin Healey have been named at inside centre and right-wing respectively, although a final decision over their participation will be made at the end of the week only.
"Daryl took a knock (dead leg) at Tuesday's training, so we're hoping that he will be fit," said Wells. "We don't have that many options available now behind the scrum. I think Pat's only got 10 fit players that are available to play, so we're going to see if Ross Broadfoot has recovered fully from his groin injury just in case Austin doesn't make it.
In other backline news, John Holtby continues on the left-wing, whilst Sam Vesty starts in the No.15 shirt, with Ireland star Geordan Murphy getting a break on the bench.
Said Wells about the Heineken Cup, which kicks off this weekend: "It's incredibly tough. We've got the defending champions, we've got ourselves as previous winners and we've got Biarritz, who were semi-finalists last year - there's an immense amount of quality in Pool 1. It's going to be tough to finish top and it's going to be tough to get a home draw in the quarter-finals, too."
Leicester Tigers: S Vesty; A Healey, S Rabeni, D Gibson, J Holtby; A Goode, H Ellis; G Rowntree, J Buckland, D Morris, M Johnson (capt), B Kay, B Deacon, L Moody, W Johnson
Replacements: R Cockerill, J White, L Deacon, N Back, S Bemand, R Broadfoot, G Murphy,
Calvisano: P Vaccari; L Nitoglia, G Raineri, C Zanoletti, A Vodo; G Fraser, P Canavosio; G Bocca, A Moretti, S Perugini, M Ngauamo, J Purll, R Mandelli, M Zaffiri (capt), C Elisara
Replacements: G De Carli, G Intoppa, M Castrogiovanni, V Bernabo, E Candiago, P Griffen, E Mulieri,
Referee: David Changleng (Scotland)