The Baggies are within striking distance of the top six as the season enters April, whilst Millwall are the side all those outside the playoff places are chasing down.
Match preview
Since Carlos Corberan earned a contract extension with West Brom at the start of February, the Baggies have been two separate entities in the Championship depending on location.
At their Hawthorns home they have been unbeatable, collecting ten points from a possible 12, however on their travels they have only picked up one point in a quartet of fixtures.
This disparity between home and away results is the sole reason why the Black Country club have not broke into the playoffs so far this term, and it looks set to condemn the club to a third-straight season at this level if it is not addressed promptly.
Currently sitting ninth in the Championship standings, Albion are five points behind Saturday's opponents Millwall who lie in sixth - it is safe to say a loss for Corberan's men in this clash could end their promotion dreams.
The Baggies last tasted defeat at The Hawthorns in the Spaniard's first match as manager against Sheffield United in October, and supporters will not be accepting of a similar result in the West Midlands on Saturday afternoon.
After three seasons of failed top-six charges, Millwall find themselves in the driving seat for a playoff position as the Championship races towards its closing stages.
Lions boss Gary Rowett warned fans of getting too carried away with his men's progress at the beginning of the campaign, however the club are now at a point where promotion is more of a realistic aim than a dream.
The West London club suffered their first truly disappointing result of the calendar year just before the international break, with a second-half Danny Ward goal condemning Millwall to a narrow loss at home to relegation-threatened Huddersfield Town.
As has often been the case in recent years, Rowett's side have been far more effective at their hostile home ground than on the road, although they are currently three games unbeaten away from The Den, having earned maximums at Stoke City and Reading in the last month.
Welsh international Tom Bradshaw and Flying Dutchman Zian Flemming have been Millwall's leading marksmen so far, with the duo having 27 Championship goals between them as their side push for promotion to the Premier League.
West Bromwich Albion Championship form:
L
W
L
W
W
D
Millwall Championship form:
W
D
L
W
W
L
Team News
West Brom will be without winger Grady Diangana for Saturday's match, with the player out for the remainder of the season due to a foot injury and the subsequent surgery.
Matt Phillips will also be a long-term user of the Baggies medical room as the veteran recovers from a muscle injury - the 32-year-old is expected back next month.
Corberan will be carefully monitoring the ongoing knee issues of Erik Pieters ahead of the meeting with Millwall, with the centre-back still suffering from the effects of a knock sustained in the loss at Birmingham City in February.
Millwall will travel to The Hawthorns without the services of Callum Styles, with the Hungary international to remain sidelined until May due to a muscle injury.
Tyler Burey scored his only goal of the season to win the reverse fixture against West Brom in October, however the winger is expected to sit out of this game as he recovers from a hip injury.
West Bromwich Albion possible starting lineup:
Griffiths; Furlong, O'Shea, Pieters, Townsend; Molumby, Yokuslu, Wallace, Swift, Albrighton; Dike
Millwall possible starting lineup:
Long; McNamara, Cresswell, Cooper, Wallace; Leonard, Saville; Honeyman, Flemming, Burke; Bradshaw
We say: West Bromwich Albion 1-0 Millwall
West Brom have been almost faultless at The Hawthorns since Corberan took over in October, and the Baggies will need that theme to continue in order to close the gap on the top six.