The Millers lost their first public friendly against Leicester on Tuesday night which was cut short after the floodlights failed with ten minutes left, but tomorrow's 3pm start should see a few more fans in attendance than the 1,100 in midweek to get a look at the new squad members.
There are no new reported injury worries for Ronnie Moore, who is continuing to hunt for a striker in the transfer market. The encouraging signs of an early partnership between Tom Elliott and Adam Le Fondre will continue and it's expected the likes of Danny Harrison, Stephen Brogan and Paul Warne will play more of a part in this game.
Dale Tonge and Tom Pope are still missing with injury until September and October respectively.
Mullins meanwhile has shrugged off a calf strain and told the clubs website: "I got a kick on it in the game at Stockport which kept me out on Tuesday but the x-rays didn't show any further problems so I am looking forward to hopefully playing against Sheffield United on Saturday.
"Pre-season is always tough but it has to be done," he added. "All the lads have been worked very hard by Warney but to be fair he has to join in himself! We have all come through and looked good which is vital ahead of a long season."
Ryan Cresswell should skipper the side from the start against his former club, with Blades boss Kevin Blackwell fetching a strong squad to Don Valley.
Entry on the gate is £10 adults, £5 concessions.