After completing the sweep of the Mariners, the A's headed to the airport to return to Oakland.
At 5:30pm on Sunday, A's outfielder Josh Reddick tweeted out a photo of the team's plane.
On the side of the aircraft, underneath the cockpit, is a message that reads: "We are SF We are Giant."
The "SF" is the San Francisco Giants logo.
The A's are 4-3 on the young season, while the Giants are 5-2.