The No. 7 Ducks host the Eagles on Saturday afternoon. And while Adams may have some insider information on his former team's tendencies, they also have an idea of his inclinations.
Either way, coach Mark Helfrich thinks the value of all this is a bit overstated.
''They're not going to drastically change,'' Helfrich said. ''What they've done on film is what they're going to do. By the same token, their personnel is a little bit different, just like our personnel is a little bit different. ... There's gonna be changes from year to year just like there's changes for us.''
Last season, Vernon helped Eastern Washington to an 11-3 overall finish; 7-1 in the Big Sky Conference. He threw for 3,483 yards and 35 touchdowns with eight interceptions, while also running for 285 yards and six touchdowns.
Vernon took advantage of an NCAA rule that allowed him to transfer as a senior after completing his degree at Eastern Washington.
There were a few tense moments in Adams' move to Eugene when he had to pass one more class to complete his coursework. He took his final exam four days into fall camp and joined the Ducks two weeks ago.
Adams was immediately thrust into competition with Jeff Lockie, who was Heisman Trophy winner Marcus Mariota's backup last season.
Mariota set a Pac-12 single-season record for total touchdowns with 58 (including 42 via pass, 15 on the run and one touchdown catch) in leading Oregon to a 13-2 overall record and a spot in the College Football Playoff championship game against Ohio State.
Lockie attempted 27 passes, completing 21 for 207 yards and a touchdown last season, playing mostly after Oregon had already built a sizable lead over its opponent. But the junior impressed many in the spring game, completing all nine of his passes for 223 yards and three touchdowns while leading his team to a 35-29 victory.
When Helfrich released his depth chart for the Eastern Washington game last Friday, Adams was listed as the starter. The coach said on Tuesday during his weekly news conference that the competition had simply shaken out.
''It happened,'' Helfrich said. ''It happened in front of everybody and it was time to go.''
Adams, an FCS All-American and two-time Big Sky Conference offensive player of the year, threw for 10,438 yards and 110 touchdowns in three seasons for the Eagles.
He grabbed attention with memorable games against the Pac-12: He passed for 411 yards and four touchdowns and rushed for 107 yards and two TDs in a 2013 win at Oregon State, and he threw for 475 yards and seven touchdowns in a 59-52 loss at Washington last season.
Helfrich seemed unconcerned about Adams making his first Pac-12 start on a team that he'd only been with a couple of weeks.
''You wait to see the guy's reaction, and it could be a reaction to three consecutive picks, and it could be a reaction to three consecutive touchdown passes,'' he said.
He also had no doubt that Adams - and the rest of the Ducks - would be ready.
''If you have to give a big motivation speech before the first game of the season,'' he said, ''you've got problems.''