This will be the second meeting between the sides in the space of three weeks, with the Union packing up a penalty-shootout victory in their Leagues Cup last-16 clash on August 4.
DC United failed to snap their five-match winless run against New York Red Bulls as they fell to a 1-0 defeat when the sides squared off last Monday.
John Tolkin came up clutch at the Red Bull Arena as he scored the only goal of the game in the 88th minute to hand the hosts their seventh league win.
Prior to that, DC United suffered a penalty-shootout defeat against Philadelphia Union in the 2023 Leagues Cup round-of-32 following a goalless 120 minutes at Subaru Park.
With Monday's result, Wayne Rooney's men have now failed to win any of their last three league matches, picking up one point from a possible nine since a 1-0 victory at Dallas on July 5.
The Black-and-Red have now lost 11 of their 25 MLS matches this season while picking up eight wins and six draws to collect 30 points and sit 10th in the Eastern Conference table, two points off the playoffs qualification spot.
Philadelphia Union, on the other hand, turned in a performance of the highest quality last Saturday when they picked up a resounding 3-0 victory over Monterey in the Leagues Cup third-place playoff.
Having edged out the likes of DC United, New York Red Bulls and Mexican outfits Tijuana and Queretaro, Philadelphia Union's quest for a first-ever Leagues Cup title came to an end in the semi-finals courtesy of a 3-1 loss against a Lionel Messi-inspired Inter Miami side.
Jim Curtin's men now turn their attention to the MLS, where they are on a run of two back-to-back wins, edging out Nashville 2-0 on July 13, three days before picking up a 2-1 victory over New York City FC.
Next up for Philadelphia Union is an opposing side who have failed to win the last four meetings between the teams, losing three and conceding 13 goals since a 3-1 victory in August 2021.
They are joined on the club's injury table by Dutch forward Nigel Robertha, who has missed the last two matches after coming off with a thigh problem against Pumas on July 30.
Veteran midfielder Alejandro Bedoya was forced off injured inside the opening half-hour against New York City last Wednesday and is out of contention for Philadelphia.
Off the back of an eye-catching cameo, Donovan could be rewarded with a starting role, which could see Quinn Sullivan, who has failed to score since last September, sweat over his place in the XI.
DC United possible starting lineup:
Miller; Ruan, Birnbaum, Williams, Hines-Ike; Canouse, Durkin, Pirani; Dajome, Benteke, Santos
Philadelphia Union possible starting lineup:
Blake; Mbaizo, Glesnes, Elliott, Wagner; Martinez, Bedoya, McGlynn; Gazdag, Sullivan, Uhre
We say: DC United 0-2 Philadelphia Union
The last five league meetings between DC United and Philadelphia Union have seen a combined 20 goals and we anticipate another action-packed contest at Audi Field. Curtin's men head into the weekend as the more in-form side and we fancy them picking up all three points.
How to watchYou can watch DC United vs. Philadelphia Union and every MLS match this season live on Apple TV. Click here for more details on how to subscribe.
For data analysis of the most likely results, scorelines and more for this match please click here.