The rookie's whirlwind day completed with his shin guards on as Mariano Rivera recorded career save No. 599 in the Yankees' 6-5 victory over the Angels.
"He's one of the best closers in the game," Romine said. "It's a tremendous honor, and I'll remember that forever."
Romine figured his season was done after wrapping up the year with four games at Triple-A Scranton/Wilkes-Barre, but the Yankees found themselves suddenly short on catching when both Russell Martin and Francisco Cervelli went down with injuries.
Unable to get through to Romine, Yankees manager Joe Girardi went to the home clubhouse and found Romine's older brother, Andrew, an infielder with the Angels, to find a better phone number to try.
"It didn't really set in -- it still hasn't set in," Romine said. "I've been on a plane, a car. I've been going non-stop since I woke up at 4:30 this morning, so I'm sure it will settle in on the bus or on the plane."
The son of former big leaguer Kevin Romine, Austin grew up about 10 minutes away from Angel Stadium in Lake Forest, Calif.
Romine said he had close to 30 friends and family members in the seats on Sunday to see his big league debut, not to mention one relative wearing an Angels uniform in the opposing dugout. Romine nearly got to bat but was left on deck when Robinson Cano struck out to end the eighth inning.
"I'm really happy for my family to be able to see both my brother and I playing big league ball together, and to play in front of my hometown," Romine said. "It's just a great moment for my family and my friends."
The Yankees were hurriedly packing their clubhouse for travel to Seattle, where they'll continue their trip on Monday, but Romine said he got some time for a brief exchange with his older brother before leaving.
"He's not a man of many words," Romine said. "He just patted me on the back and said, 'Good job.' Big brother, that means a lot."