Lunt's loan spell is due to expire after the FA Cup tie against Millwall but the Runcorn midfielder is ruled out after having a double hernia operation.
29-year-old Lunt is in his third spell at Gresty Road and only made 4 apperances for the Railwaymen one of which was a sub against Stockport County.
Lunt is currently recovering from the operation and has been told by Owls manager Brian Laws that his present contract at Hillsborough will not be renewed when it expires this coming summer.
Gradi told the official site: "People know what I think about Kenny. I like having him here and out on the pitch.
"He can play in a variety of roles and can dictate the play. He has great experience and has been a good addition for us."