Left-back Ben Thatcher is Town's man concern ahead of Saturday's trip to Preston North End after hurting his foot during last week's win at QPR and aggravating it further in training. The Blues will also be without Danny Haynes and Iván Campo.
Boss Jim Magilton has a couple of options should Thatcher fail to make it. David Wright switching to the left and Moritz Volz coming in on the right looks the most obvious, while Pim Balkestein could come in on the left, although the Dutchman has been less favoured as a full-back in recent months.
Balkestein could return to the centre of the defence if Magilton prefers to switch Alex Bruce from centre-half to right-back, but Wright's switch looks most likely.
Elsewhere, Town are unlikely to make too many changes after last week's impressive win. Skipper Gareth McAuley will remain at the heart of the defence and Richard Wright in goal. Shane Supple will keep his place on the bench while the Blues find cover so the Irish U21 international can join Grimsby on loan.
In midfield, Jon Walters may be considered fit enough for a start on the right after his recent bug and Luciano Civelli may be the man to drop to the bench with David Norris switching to the left of midfield.
Alternatively, the Town boss may prefer to move Norris in the centre and leave out Alan Quinn. This would be harsh on the Irishman, who has impressed alongside one-time Preston loanee Tommy Miller in recent weeks.
Danny Haynes is making progress after injuring his hamstring in the Blackpool game and could be available for Tuesday's match against Southampton. Iván Campo, out for most of the year with a calf injury, is back in full training and could be in reserves action in midweek.
Up front, Pablo Couñago and Jon Stead look set to continue after proving a handful for QPR's defenders last week when they both scored.
With assistant manager John Gorman away this week, although back with the squad for the game, specialist skills coach Steve Foley gave the Town management's view of the trip to Deepdale: "It would be a good scalp to get.
"These are the genuine six-pointers because we are not just clawing our way up, but we are pulling teams back too.
"If we can win we go above them, but they will be saying they can go six points clear of us.
"The players will be up because it is a tough game. We just have to play right on the day.â€Â
Preston are currently sixth on 53 points, four places and three points ahead of the Blues, who have a superior goal difference. The Lilywhites have been impressive at home, winning 12, drawing two and losing three, and manager Alan Irvine hopes to keep this run going: "Our home form has been excellent and I am hoping that will continue.
"If we can keep that up between now and the end of the season, coupled with some good results on the road, I'm sure we will be in a very good position come the end of the season.â€Â
Irvine says Saturday's game won't decide his club's fate: "If we win this one it doesn't mean we are going to finish in a play-off position.
"And if we lose it then it doesn't mean we are not going to make the top six. But if we do win it opens up a big gap between us and Ipswich. If we don't, then they will be level."
Irvine is expected to have striker Neil Mellor back in his squad after the former Liverpool man underwent a double hernia operation last month, although a place on the bench looks most likely.
Defender Callum Davidson could also return after a calf problem, but midfielder Chris Sedgwick has undergone hernia surgery and is out for five weeks.
Midfielder Barry Nicholson and defender Andrew Davies, on loan from Stoke, are both expected to be OK after picking up knocks in last week's 3-1 defeat at Southampton.
Liam Chilvers (hamstring), Neal Trotman (hernia), Michael Hart (ankle) and Wayne Henderson (back) are all longer term absentees.
Former Town keeper-coach Andy Rhodes will be reunited with his old colleagues on the touchline having joined North End last summer after leaving the Blues. Tommy Miller had a loan spell at Deepdale while a Sunderland player but no other current Blues has appeared for the Lilywhites and no current Preston player has been with Town.
The Blues enquired regarding the availability of Preston keeper Andrew Lonergan during the close season with West Ham stalling on the Richard Wright deal, while Mellor was repeatedly linked with loan moves to Town during his Liverpool days.
Preston are slightly ahead of the Blues historically. Town have won eight games (seven in the league), Preston nine (eight), while six matches have ended in draws (six).
On the opening day of the season the Lilywhites came from behind to win 2-1 at Portman Road via goals from Paul McKenna and Simon Whaley, Kevin Lisbie having put the Blues ahead inside two minutes.
At Deepdale last April, the sides played out a 2-2 draw, Tommy Miller, who always seems to net against Preston, and Jon Walters scoring for Town and Chris Brown and Neil Mellor for the Lilywhites.
Town's last win at Preston was a third round FA Cup tie in January 1980 in which goals from Paul Mariner (2) and Alan Brazil saw the Blues to a 3-0 victory.
Saturday's referee is Steve Tanner, a member of the Select Group of Premier League officials and who is also on the FIFA list. Tanner has shown 68 yellow and six red cards in 23 games so far this season.
His last Town game was the 2-0 home defeat to Wolves in August in which he red-carded Alex Bruce for a two-footed lunge and booked Pablo Couñago, Veliche Shumulikoski and two Wolves players.
Likely squad: R Wright, Supple, D Wright, Thatcher, Volz, McAuley, Bruce, Balkestein, Miller, Quinn, Garvan, Shumulikoski, Norris, Walters, Civelli, Couñago, Stead, Lisbie, Bowditch.