Striker Zohore and midfielder Gunnarsson both missed last weekend’s 1-0 victory at Middlesbrough with ankle injuries.
The pair have returned to light training, but Bluebirds boss Neil Warnock is reluctant to rush them back and Cardiff could be unchanged after their Riverside win.
Goalkeeper Lee Camp’s return has been delayed by three weeks after he pulled a thigh muscle just as knee and groin issues had cleared up.
Millwall’s Steve Morison is fit to start after returning in last week’s 2-0 defeat of Birmingham.
His availability means manager Neil Harris a near-fully-fit squad from which to choose.
His only absentees are Shaun Williams and Byron Webster, who will respectively be missing until Christmas and the end of the season, both owing to knee injuries.
The Lions are chasing their first away win of the season.