Gonzaga has a home game against Portland and road games @San Francisco and @San Diego to finish the season. Santa Clara gets San Diego at home before finishing @Pepperdine and @Loyola Marymount.
Santa Clara lost to Loyola Marymount at home in January, a result that appears to be Gonzaga's last, best hope to get a share of the conference title.
Having no idea how the tie-breaker for seeding in WCC Conference Tournament would work in the case of co-champions who split their regular season meetings (with Santa Clara a single point per 100 possessions to the good over the two games), let's speculate on which team would be favored to gain the WCC's automatic bid.
Wins: vs. UNC (+10), vs. Texas (+11), @Santa Clara (+13), @Portland (+21), @Stanford (+4), @Pepperdine (+37)
Losses: vs. Butler (-17), @Washington State (-14), vs. Georgia (-13), vs. Duke (-19), vs. Nevada (-12), @Virginia (-32), @St. Mary's (-7), @Loyola-Marymount (-8), Santa Clara (-14)
Gonzaga wouldn't figure to have much of a chance hosting Memphis this Saturday with Josh Heytvelt. In the two games without him, they've barely topped a point per possession offensively. If Heytvelt is out for the rest of the year, I seriously doubt the selection committee takes Gonzaga's at-large bid seriously.
Wins: vs. Alabama State (+43), @Pacific (+27), @Stanford (+24), @San Diego (+17), @San Francisco (+6), @St. Mary's (+9), @Portland (+39), @Gonzaga (+14)
Losses: @Cal (-36), Nevada (-16), @Missouri State (-37), @Kentucky (-18), Air Force (-58), Gonzaga (-13), Loyola-Marymount (-4)
Santa Clara has almost caught Gonzaga in the WCC average efficiency margin standings, and, though they have an even worse resume for an at-large bid than does Gonzaga, I think they would have to be favored over a Heytvelt-less Zags squad in the WCC Tournament.
If they can't avenge their home loss to Loyola Marymount, though, I'd probably waffle on my speculative outcome.