With 14 wins and 10 draws from 30 games, the Rapids are six points clear of the Timbers in the table, but have won only once in their last four games.
Portland, meanwhile, saw their four-game winning run end at the hands of LA Galaxy last weekend before going on to lose to Vancouver on Thursday.
It halted their upward spiral and kept them from closing the gap on their western rivals.
Both sides will be eager to return to winning ways here, although poor defenses in both camps make for an enticing clash.
Colorado have conceded eight times in their last four games, including thrice each to Seattle Sounders and Real Salt Lake, while Portland aren't far behind with six.
Colorado Rapids vs Portland Timbers Head-To-Head
Colorado Rapids have won exactly a third of their last 24 games against Portland, who've won 10 times during this period.
However, their last clash, coming just over a month ago, ended in a 2-2 draw.
Colorado Rapids Form Guide (all competitions): W-L-W-L-D
Portland Timbers Form Guide (all competitions): W-W-W-L-L
Colorado Rapids vs Portland Timbers Team News
The Rapids have a clean bill of health going into Sunday's game and manager Robin Fraser can call upon his best XI.
Unfortunately, the Timbers have not had as much luck with injuries, with four players currently in the treatment room.
Claudio Bravo and Bill Tuiloma are doubtful due to thigh problems.
Injured: Ismaila Jome, Jeff Attinella, Andy Polo, and Eryk Williamson
Colorado Rapids vs Portland Timbers Predicted XI
Colorado Rapids (4-4-2): Clint Irwin; Keegan Rosenberry, Danny Wilson, Auston Trusty, Kellyn Acosta; Michael Barrios, Mark-Anthony Kaye, Jack Price, Jonathan Lewis; Dominique Badji, Andre Shinyashiki.
Portland Timbers (4-2-3-1): Steve Clark; Josecarlos Van Rankin, Larrys Mabiala, Dario Župarić, Pablo Bonilla; George Fochive, Cristhian Paredes; Dairon Asprilla, Sebastián Blanco, Yimmi Chará; Felipe Mora.
Colorado Rapids vs Portland Timbers Prediction
Both sides rank highly on the table but their form of late hasn't been inspiring.
They've struggled to knit victories together and have also conceded a handful of goals in their last few games.
A high-scoring contest is on the cards that may end in a share of the spoils.
Prediction: Colorado Rapids 2-2 Portland Timbers