MLS bottom-dweller D.C. United continues seeking salvation in the 100th annual U.S. Open Cup with a semifinal against the Chicago Fire.

Where: Toyota Park, Bridgeview, Ill.

When: 8:30 p.m. ET

Live streams: www.dcunited.com, www.chicago-fire.com, www.ussoccer.com

At stake: Berth in the championship match against the Portland Timbers or Real Salt Lake. If Portland advances, the final will be played Sept. 24 at Jeld-Wen Field. If RSL goes through, Rio Tinto Stadium is the venue Oct. 1.

DCU: Willis; Korb, Jakovic, Woolard, Riley; DeLeon, Kitchen, Thorrington, Porter; Silva, De Rosario. Subs: Hamid, Kemp, White, Pontius, Nyassi, Jeffrey, Doyle.

CHI: Johnson; Anibaba, Berry, Soumare, Segares; Nyarko, Larentowicz, Alex, Duka; Rolfe, Magee. Subs: Tornaghi, Jumper, Pause, Paladini, Lindpere, Amarikwa, Anagono.

Your pregame, in-game and postgame thoughts are welcome in our comments section.