The Warriors pair are among 10 new faces following defeat against Stade Francais last time out in Pool One.
"We don't know a great deal about them, certainly not as much as we did against Stade Francais," Warriors forwards coach Phil Davies said.
"But we do know they are a side that like to throw the ball about and play."
Captain Chris Pennell and wing Tom Arscott are the only backs to hang onto their places, as Gray, Tu'ipulotu, fit-again scrum-half Jonny Arr, Josh Drauniniu and Andy Short are called up.
A new-look pack features five changes as prop Bruce Douglas and hooker Chris Fortey join Oliver Tomaszczyk in the front row.
Ben Gulliver is named at lock while Sam Betty and Adam Balding will line up in the back row alongside Matt Kvesic, who impressed against Stade.
Young front row duo Ollie Hayes and James Currie are among the replacements alongside Miles Benjamin, who is free to play again after serving a one-week ban.
"We are stepping into the unknown a bit as we haven't seen much of what the team can do," said Arr.
"It could be a banana skin but we will go out there and push for that win and hopefully kick start a bit of a winning roll."
Crociati Parma: Rubini, En Naour, Vengoa, Damiani, Alberghini, Morisi, Zucconi, Singh, Manici, Coletti, Van Vuren, Fletcher, Mandelli, Delnevo, Cicchinelli.
Replacements: Sciacca, Goegan, Tripodi, Contini, Ruffolo, Ireland, Farolini, Magri.
Worcester: Pennell, Arscott, Short, Tu'ipulotu, Gray, Arr; Douglas, Fortey, Tomaszcyk, Gulliver, Gillies, Betty, Kvesic, Balding.
Replacements: Hayes, Taumoepeau, Currie, Lutui, Abbott, Frost, Goode, Benjamin.
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