Why did Sergio Romo wear a special hat in his farewell game? Unique headgear in his final Giants appearance made his exit more memorable 

Sergio Romo was the living embodiment of the Moneyball quote, "How can you not be romantic about baseball?" On Monday night, the 40-year-old pitcher made one final appearance for the San Francisco Giants before being pulled from the game by former teammate Hunter Pence. Romo's emotional exit from the game brought an end to the his 15-year MLB career.

Romo played 15 seasons for eight different organizations, including spending his first nine years with the San Francisco Giants.

The reliever shared a goodbye note Monday to San Francisco on The Players’ Tribune:

“Dear San Francisco, Tonight I get to do something one last time — something that’s been one of the biggest honors of my whole life: I get to put on a Giants jersey. And before I go do that, I just wanted to write this letter, and share some thoughts with you all.”

While the send-off for Sergio Romo was emotionally perfect, he later revealed a small detail that made the night even more special. Romo showed reporters the special hat he decided to wear during his final appearance.

The hat he wore during his final pitching performance featured dozens of autographs inside and on the brim. Knowing his return to the San Francisco Giants was simply to retire with the team where he spent the majority of his career and won three World Series, Romo decided to capitalize on that moment as his retirement approached.

During spring training, whenever a child asked Romo for an autograph, he asked them to sign his hat first.

“If this is the last hat I was going to wear in the big leagues ... I figured it would be nice to not go in there alone,” he said.

A look at Sergio Romo's MLB career

After being drafted by the San Francisco Giants in the 28th round in 2005, Romo quickly became an important member of the team, helping them win the World Series in 2010, 2012 and 2014. He also made his only All-Star appearance as a member of the Giants in 2013.

"15 seasons. 3 rings. 1 Sergio Romo," MLB tweeted.

Romo posted a career record of 42-36 with a 3.21 ERA and 137 saves over 821 appearances spanning 722 2/3 innings. The veteran relief pitcher spent time with eight different franchises: the Giants, Minnesota Twins, Tampa Bay Rays, Oakland Athletics, Los Angeles Dodgers, Miami Marlins, Seattle Mariners and Toronto Blue Jays.

Last season, Romo made 23 appearances with the Mariners and Blue Jays.