MILLWALL right-back Mahlon Romeo will miss the play-off campaign after he received a three-game ban for his red card at Gillingham last Sunday.
Carlos Edwards, who last started for the Lions in the 2-2 draw at Swindon on March 12, when he played at left-back, will likely be Romeo's replacement at Bradford this Sunday.
Tony Craig, Sid Nelson and Jimmy Abdou are other options.
Lee Gregory (above), who came off the bench to score a 98th-minute winner against the Gills, should be in contention for a starting spot after proving his fitness following hernia surgery.
If Harris decides not to risk Gregory from the start then Aiden O'Brien could continue alongside Steve Morison with Shane Ferguson and Chris Taylor in the wide midfield positions.
Harris is pleased with his options ahead of the Valley Parade clash.
"Fergie and Tayls have been excellent," Harris said. "There's competition for places there with Fred Onyedinma and Ed Upson. Shaun Williams is back fit. He's chomping at the bit to get back in."
Bradford striker Billy Clarke is a doubt with a fractured cheekbone. There is also a concern over on-loan West Ham defender Reece Burke, while James Hanson was having a scan this week on a calf problem.
Phil Parkinson's side have won seven consecutive games at home where they also haven't conceded a goal in over two months.
The records of both sides in 2016 are almost identical: Both were on 34 points at the beginning of the year, both have won 14 games, with Millwall drawing one more to finish a point ahead of Bradford in the League One table.
Millwall record against Bradford:
Won 17 Drawn 15 Lost 10
(Last five fixtures)
Sky Bet odds:
Bradford 6/4 Draw 9/4 Millwall 9/5
Probable Bradford team:
4-4-2: Williams; Darby, McArdle, N Clarke, Meredith; McMahon, Evans, Cullen, Reid; Morais, Hanson.
Probable Millwall team:
4-4-2: Archer; Edwards, Webster, Beevers, J Martin; Taylor, Thompson, Abdou, Ferguson; Gregory, Morison.
This season's league meetings
Millwall: Archer; Edwards, Craig (Webster, 56), Beevers, J Martin; O'Brien, Williams, Saville, Ferguson (Onyedinma, 62); Gregory (Pavey, 90), Morison.
Bradford: Williams; Darby, McArdle, Burke, Meredith; McMahon, Liddle, Evans, Reid (Marshall, 72); Hanson, Cole (B Clarke, 80).
Bradford 1 (Davies, 79)
Bradford: Williams; Darby, N Clarke, Burke, Meredith; McMahon, Knott, Thorpe, Reid (Morris, 92); Proctor (Hanson, 75), B Clarke (Davie, 75).
Millwall: Archer; Romeo, Webster, Beevers, J Martin; Onyedinma (Philpot, 83), Thompson, Williams, Upson (Taylor, 57); Morison, O'Brien (Gregory, 65).
Millwall 0-0 Bradford
Bradford 1-0 Millwall