The team with the third-fewest points in MLS visits the team with the second fewest on Saturday night.
Chivas began its two-game homestand on Wednesday night with a 2-0 loss against Portland, and will be hoping for a better result against the struggling Union (10:30 p.m. ET, MLS Live).
Philadelphia will be playing in the same stadium where it was an unwitting participant in history Sunday. Landon Donovan broke the MLS all-time scoring record in a 4-1 Galaxy win over the Union.
The Goats will be missing Bobby Burling, who was sent off in the loss against Portland. Both teams will be mostly full-strength in the injury department, with Thomas McNamara and Andrew Jean-Baptiste long-term absences for Chivas.