Both on-loan centre-halves Simon Ainge and Connor Essam are unavailable, with Ainge cup-tied after featuring for previous club Guiseley, and Gillingham not allowing Essam to feature.
Kovacs hasn’t started since the 4-1 defeat at Grimsby six games ago, but came through 90 minutes of a development game against Charlton Athletic on Tuesday afternoon.
Boss Paul Buckle said: “Janos got a much needed 90 minutes and with Ainge and Connor Essam not being able to play Saturday, certainly he has a chance.
“Janos has had his rest now and has got an opportunity to come back in fresh and show what he’s all about.
“He had a brilliant season last year and I’m sure the rest will have done him good and he can find the levels he got to last season.
“It’s worked quite well as Ainge and Essam have done excellently, we’ve won four out of five, but coming back, the big man won’t let us down.”
Buckle does face something of a defensive selection headache with Alex Lacey absent and Dean Beckwith doubtful after both came off at half time against the Addicks.
The boss continued: “Dean has come back from a groin (injury).
“It’s stiffened up again, so that wasn’t great. We took no chances and now we’ll have to wait and see how that is.
“It was a little bit annoying that it flared up again, so we’ll see how Beckwith goes.
“Alex Lacey has had no luck at all.
“Every time he’s tried to get up and running he’s fallen over with either illness or injury.
“He dislocated his shoulder earlier on when he was doing ever so well. Then he’s come back and been part of the squad, before getting a bad illness.
“He didn’t look great at all in himself (at Charlton), so we’ve got to be careful with that one.
“There’s nothing worse than playing when you’re ill and I don’t think he will be strong enough to be involved on Saturday.”
On the tie itself, which has been brought forward to a 1pm kick-off on police advice, Buckle added: “It’s the FA Cup, it’s the most famous cup in the world and the biggest trophy for lower levels.
“We’re not blessed with a squad of 30 or 35 where we can rotate, players will have opportunities on Saturday and they are in a good place at the moment, with the return of points in the league and late goals on Saturday.”
The match will also be the first time Town have come up against former boss Richard Money, who is now head coach at the Abbey, since he left Kenilworth Road in March 2011.
That was of no significance to Buckle though as he added: “All of that’s before me, my focus is on training Thursday and Friday, getting us prepared, trying to get on the front foot to go and enjoy the FA Cup.
“It’s a great competition, I want us to go and express ourselves and try to win.”
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