Sheffield United manager Danny Wilson must decide whether to recall defender Neill Collins to his starting line-up.
Collins has been sidelined with an infected toe, but stepped off the substitutes bench for the final 13 minutes in the weekend win at his former club Preston and could return alongside Harry Maguire in central defence.
Wilson, who has no new injury or suspension problems, also has the option of recalling strikers Shaun Miller and Chris Porter, who have waited patiently on the bench for most of the season.
But the Blades extended their unbeaten run to 15 games in all competitions this campaign with victory at Preston and Wilson is unlikely to make too many changes as his third-placed side have dropped just four points from the last 18 available.
Defender Lecsinel Jean-Francois will be sidelined for a further two months after sustaining cartilage damage in his first match back from a long-term knee injury at Notts County in last week's Johnstone's Paint Trophy win.
Walsall boast a fully-fit squad.
Manager Dean Smith is likely to keep faith with the same XI who started Saturday's 2-2 draw at home to Crewe, in which the visitors nicked an injury-time point.
Smith watched his young side take command by establishing a two-nil advantage before the Alex reduced the arrears by half-time, and, having made three substitutions in the final 16 minutes, Walsall were eventually pegged back to settle for a point.
Defender James Chambers could be pushing for a place on the bench having recovered from the thigh injury which has sidelined him for the past two months.
Striker Will Grigg told the club's official website: "There's no reason to change the way we've been playing; we go into Tuesday's game looking forward and ready for the challenge that awaits us.
"It's a great stage to play on. We'll go there full of confidence and with a determination to make the most of it and bring home the right result. It's a big opportunity for us against a side who are yet to taste defeat this season."
