OAKLAND -- Since the A’s were formed in 1901, there has been a bevy of spectacular individual seasons from the many legends to play during the club’s stints in Philadelphia, Kansas City and Oakland.

Those are even more special when they come in a player’s first season with the team, whether it be a rookie making a good first impression or a recent acquisition via trade or free agency living up to high expectations. Here's a look at the Top 5 individual debut seasons in A’s history:

1. Frank Thomas, 2006
Released by the White Sox following their 2005 championship season, Frank Thomas was viewed as a player on the decline who was nearing the end of his career. The A’s signed the 38-year-old designated hitter to a one-year, $500,000 deal with incentives for the ‘06 season and soon found out “The Big Hurt” had plenty left in the tank. Thomas slugged a home run off Randy Johnson on Opening Day at the Coliseum against the Yankees, kicking off a season that would see him finish fourth in American League MVP Award voting as he slashed .270/.381/.545 with 39 homers and 114 RBIs over 137 games. After hitting a combined 30 home runs over the previous two seasons, his power was back. Thomas even set an A’s record that year by bashing a home run in six consecutive games.

The A’s won the AL West that season, putting Thomas in the postseason for just the third time in his Hall of Fame career. Though Oakland was eliminated by the Tigers in the AL Championship Series, Thomas exploded in the AL Division Series against the Twins, batting .500 with a pair of home runs in a three-game sweep. The career resurgence earned him the AL Players Choice Award for Comeback Player.

2. Rube Waddell, 1902
When A’s owner Connie Mack managed to lure Waddell out of a contract with the Los Angeles Loo Loos, even he probably didn’t foresee the immediate impact the Hall of Fame left-hander would make.

Though he didn’t pitch in his first start with the A’s until June, Waddell ended up appearing in 33 games that season. He went 24-7 with a 2.05 ERA and an AL-leading 210 strikeouts. Waddell’s 9.4 bWAR for the 1902 campaign is the highest by a pitcher in his first season with the A’s in club history. The dominance by Waddell helped lead the A’s to an AL championship that year.

3. Mark McGwire, 1987
McGwire technically made his debut in 1986, but he only appeared in 18 games that year and maintained his rookie status for ‘87, when he truly made his presence felt. Earning an All-Star selection with 33 homers by the break, the slugger finished the year leading the Majors with 49 home runs. McGwire earned AL Rookie of the Year honors and a sixth-place finish in MVP voting as he also drove in 118 runs and slashed .289/.370/.618. His 49 home runs stood as the single-season record by a rookie until Yankees star Aaron Judge hit 52 in 2017.

4. Khris Davis, 2016
During his first three Major League seasons with the Brewers, Davis displayed solid power numbers. But upon his arrival to Oakland via trade prior to the 2016 season, Davis burst onto the scene by mashing a team-high 42 home runs. His 102 RBIs also marked the first time an A’s hitter had reached 100 RBIs in a season since Thomas’ ‘06 campaign.

5. Kenny Rogers, 1998
Rogers will forever be an answer to A’s trivia after he was acquired from the Yankees for Scott Brosius in what was Billy Beane’s first trade as general manager of the A’s. The left-hander went 16-8 with a 3.17 ERA, leading the club in wins and innings pitched (238 2/3) that season. Rogers went on to pitch in 19 games for Oakland in ‘99 before getting traded to the Mets at the Deadline in a deal that landed the A’s outfielder Terrence Long.