JED Wallace returns this weekend and should go straight back into the Millwall side that takes on Hull at The Den on Saturday.
Jiri Skalak is set to miss out with a foot injury and joins goalkeeper Frank Fielding in the treatment room.
Wallace served a three-match ban for his sending-off against Sheffield Wednesday.
"We performed very well at Middlesbrough without him, which was pleasing to see," Harris said. "What Jed will add for Hull is a fresh impetus to the group, a hunger to put right what he did wrong after getting a red card.
"He certainly comes into the mix and we have to see how the boys have responded from playing a lot of games over this period.
"We've had two good home victories but we also want to try to be better as a group. As ever it's about picking a team to compete against Hull and cause them problems. It's also about who's fresh as well, which is vital."
Harris has plenty of options this weekend and the performances of Jayson Molumby and Jon Dadi Bodvarsson at Oxford will have given him plenty to think about. Bodvarsson scored twice at The Kasssam Stadium on Tuesday, while Tom Bradshaw is also pushing for a starting spot.
Billy Mitchell was also impressive against Oxford but the club will take their time with his development.
Hull also lost on penalties in the second round of the EFL Cup midweek, after a 2-2 draw at Preston.
Gavin McCann's side have won only one of their five league games this season, 2-1 at home to Reading. They have lost their last two Championship games, against Bristol City and Blackburn at the KCOM Stadium.
Eric Lichaj returns from injury, but midfielder Dan Batty is out.
Possible Millwall starting XI: Bialkowski; Romeo, Pearce, Cooper, M Wallace; J Wallace, Thompson, Williams, Mahoney; O'Brien; Smith.
Match odds: Millwall 11/10 Draw 11/5 Hull 13/5
Image: Millwall FC