What a difference a matter of weeks can make.

It was only 17 days ago that the Oregon football program was riding a wave of momentum that was as high as it had been in four years. The Ducks were not only fresh off a win over a top 10 opponent in Washington, but the victory also helped take the sting out of the previous two meetings against their rivals from the north; games in which Oregon was utterly dominated by a combined score of 108-24.

With their Pac-12 title hopes more or less resting in their hands, Oregon had made its way back to a place that was familiar to those who pined for a return to the days when Oregon was both the toast and envy of the conference, if not much of the nation.

That return to prominence has proved to be brief, however.

With hopes of staking a bigger claim to the inside track to the Pac-12 North division title, Oregon’s performance on the road at Washington State fell flat after the Ducks found themselves in a 27-point halftime hole that couldn’t be overcome despite a rousing second half effort.

Then, with their hopes for division title on life support, things went from bad to worse against a beleaguered Arizona Wildcats squad in Tucson this past Saturday. Oregon not only got beat, but looked thoroughly uncompetitive in a 44-15 loss to a 3-5 team who had lost three of their last four contests, and sported the Pac-12’s second-worst defense entering the game. That same defense held the Ducks to a season-low 270 yards of total offense.

It’s only fitting then that with the season at a crossroads eight games into Mario Cristobal’s voyage as Oregon head coach, that the Ducks play host this Saturday to the coach who became the unofficial measuring stick by which all proceeding Oregon head coaches are judged by.

Welcome back to Eugene, former Oregon and current UCLA head coach Chip Kelly.

Similar to Cristobal, Kelly endured struggles of his own in his first year as Ducks head coach. Oregon’s unflattering performance in Kelly’s debut at Boise State in 2009 quickly turned to embarrassment after the game was marred by the infamous postgame melee featuring LeGarrette Blount and Byron Hout. Cristobal has so far avoided such a public relations nightmare, but unlike the 2009 team which rebounded in convincing fashion before ultimately making its way to the Rose Bowl, Cristobal’s team has fallen off a cliff with four games left to play.

From the top down, the Ducks have looked like a dramatically different team since the halfway point of the season. Justin Herbert looks unsettled, Oregon’s physical approach to the ground game lacks considerable bite, the defense is struggling to get off the field, and the offensive game plan is devoid of imagination and identity.

Making matters (potentially) exponentially worse is the fact that on Monday, Cristobal revealed that both Herbert and leading receiver Dillon Mitchell were in concussion protocol, which means the status of each player’s availability for Saturday’s game is now shrouded in serious doubt.

With Herbert and Mitchell in the lineup, the Ducks likely remain the considerable favorite, though the offense’s recent struggles inspires little confidence that they’ll actually play to such a level.

Without Herbert and Mitchell, it’s not a stretch to say that Saturday’s game versus UCLA suddenly becomes something that more closely resembles a toss-up in Kelly’s return to Autzen.

Since his arrival in Westwood, Duck fans have had Saturday’s game circled for obvious reasons as Kelly, who is still beloved and revered by fans in Eugene, sets to make his much anticipated return to a place he helped elevate to levels of unprecedented success. However, in the midst of the indisputable storyline that dominates this game, the trajectory of Oregon’s season and outlook of the program’s foreseeable future unexpectedly hangs in the balance.