Wellens joins Andy Drury in the heart of the Ipswich midfield while Campbell leads the line alongside Daryl Murphy.
Michael Chopra has been left out of the squad entirely after his troublesome week, where he was charged with race-fixing. The frontman is joined by Guirane N'Daw in missing out completely, despite starting at Brighton in midweek.
Another new loanee, Bilel Mohsni, is on the bench for the Tractor Boys.
Ipswich: Loach; Edwards, Chambers, Higginbotham, Cresswell; Emmanuel-Thomas, Wellens, Drury, Martin; Campbell, Murphy
Cardiff: Marshall; McNaughton, Hudson, Connolly, Taylor; Mason, Gunnarsson, Whittingham, Noone, Cowie; Helguson