And that has put his ever-present record at Latics in doubt after starting 90 consecutive games since joining the club almost two years ago.
But what could lean in his favour is he has had an extra day to shake off the injury, with the rest of the Championship playing yesterday.
Latics boss Paul Jewell said: "Jimmy has hurt his calf muscle and at the moment I have to say he is struggling for the Wolves game.
"We'll give him every chance to get fit and it's a case of waiting to nearer to kick-off to see how he is.
"It's a worry when any of your players get injured, although I thought the midfield did well at Sheffield United even after Jimmy went off."
Mike Flynn replaced Bullard on Saturday and caught the eye with an energetic display, setting up the second goal for Nathan Ellington.
He is likely to get the nod tonight if Bullard isn't fit, although Alan Mahon – left out of the 16 at Bramall Lane – is another option.
Bullard was linked over the weekend with a January switch to either Crystal Palace or Everton.
But the report appears to be only paper talk, with Jewell saying at the end of last week he hadn't received a single enquiry about any of the squad.
And with chairman Dave Whelan issuing a "hands off" warning last month, it's
unlikely a top-flight club would get any joy if they made an approach.
The club are also believed to have offered Bullard an extension to his current contract which runs until the end of next season.
On the selection front for tonight's game (kick-off 8pm), skipper Matt Jackson will return to the centre of defence in place of Ian Breckin who serves a one-match suspension for clocking up five bookings.
Jackson was on the bench at Burnley and Sheffield United with Jewell preferring the Breckin/Emerson Thome partnership.
Tonight will be the first time that Jackson and Thome have started a game together, injuries to both players at various stages this season previously keeping them apart.
Jewell expects Wolves to be much tougher opposition than their lowly league position suggests.
Glenn Hoddle's side are in 18th place and arrive at the JJB Stadium on the back of five consecutive 1-1 draws.
Jewell said: "This is a massive game and I still find it incredible that Wolves are down at the wrong end of the table.
"They have some good
players and I won't write them off for a play-off place despite where they are at the moment.
"Much has been made of the fact they've been drawing games, but runs like that do come to an end as we found on New Year's Day when we halted a run of three defeats.
"This has all the ingredients of being a decent game. There should be a good crowd, and hopefully we can pick up three points to follow on from the excellent win at Sheffield United.
"Hopefully the little blip we had over Christmas is now behind us, and while I would like us to be top of the league, we aren't in a bad position.
"We are fighting against our weight in this division with teams such as Sunderland, Ipswich, Sheffield United, West Ham, Leicester, Wolves and Leeds, who have a big history and big crowds.
"We must be progressing well as we have been disappointed to have dropped down a couple of places."
In fact, after yesterday's games, Latics have hung on to second place as Sunderland were held 1-1 at home to lowly Gillingham and Reading being beaten 1-0 when hosting Derby.