Didier Drogba, Ashley Cole and Michael Essien all face fitness checks ahead of the game.
Striker Drogba picked up a knock in training on Friday, while full-back Cole and midfielder Essien were unable to train after hurting themselves in Wednesday night's shock Premier League defeat at Wolves.
Alex returned from Brazil on Friday and will continue treatment on the knee injury that is expected to keep him out for another three or four weeks, while John Obi Mikel (knee), Yury Zhirkov (calf) and Yossi Benayoun (Achilles) remain sidelined.
Ipswich caretaker manager Ian McParland will be without three key men for the clash with the Blues.
Sunderland midfielder Jack Colback has been recalled early from his loan spell by Steve Bruce while Plymouth striker Rory Fallon is also ineligible after playing for Argyle in an earlier round.
Midfielder Grant Leadbitter is also absent as he begins a three-match ban following his last-minute dismissal against Nottingham Forest on Monday.
However one boost for McParland, who is in temporary charge after the departure of Roy Keane on Friday, is the news that Celtic defender Darren O'Dea and Tottenham midfielder Jake Livermore have both been given permission to play by their parent clubs.
Captain Gareth McAuley has made a surprise early return following two months out with an Achilles injury and the Northern Ireland defender is expected to keep his place. Goalkeeper Brian Murphy has undergone surgery on an ankle problem he picked up before Christmas and will be out for at least three months.
Winger Shane O'Connor also remains on the sidelines with a ruptured and dislocated shoulder joint and will miss six weeks. Young midfielder Luke Hyam is out with a hamstring injury to complete a lengthy injury list.
Chelsea (from): Cech, Ferreira, Bosingwa, Ivanovic, Bruma, Terry, Cole, Ramires, Kalou, Essien, Lampard, Anelka, Sturridge, Drogba, Malouda, Turnbull, Van Aanholt, McEachran, Mellis.