The 24-year-old had an important task in front of him.
"I have to go buy a phone card right now," he said.
That's because Romero was planning on calling his family in Venezuela to tell them the good news: He made the D-backs' Opening Day roster, edging out veteran Trot Nixon.
"I feel really excited," said Romero. "Really big surprise for me. This year, I tried to be ready and I felt comfortable at home plate."
When camp opened, it didn't look like Romero had much of a chance at making the team, but after a strong performance March 2 in the team's game in Hermosillo, Mexico, he started to appear on manager Bob Melvin's radar.
Not long after that it became apparent that infielder Chad Tracy's surgically repaired right knee was not going to be ready for the opener.
Meanwhile, Romero, who hit .310 for Triple-A Tucson last year, kept hitting, and the lefty swinger hit lefties as well as righties.
"He just kept knocking on the door," Melvin said. "And he kept himself prepared, got big hits in games and got some starts because of it and getting hits in those games. He showed he could face left-handed pitching and be successful off that. [He] was always prepared whether he was starting, coming off the bench or pinch-hitting. He runs the bases well, does a lot of things that can factor into a game."
Romero will join Jeff Salazar, Chris Burke, Robby Hammock and Augie Ojeda on the bench, while Nixon was said to be contemplating whether or not to accept an assignment to Tucson.
"He understood," Melvin said of Nixon, who was signed as a free agent just prior to the team's first full-squad workout. "He actually said, 'Alex had a great camp, he deserves to be on the team.' He's a great guy. He understood that when he first came here the odds were long, but the longer he was here the better he fit in and the better his chances of making the team were."
Nixon was thought to have the edge in the two-way battle given that he had more experience coming off the bench than Romero did and he had learned to play first base, something that Romero is not able to do.
But in the end, the club decided to go with the player that had the best spring. That means that Burke, who can play seven positions and has swung a hot bat this spring, will get the bulk of the at-bats behind Conor Jackson at first base.
"I have to find a way to get Burke into games, and first base is going to be one of those places," Melvin said. "I'm going to try to move him around as much as I can. He's basically an everyday player that doesn't have an everyday job."
With the position player portion of the roster set, the D-backs still must determine who will fill the final two spots in the bullpen. Dustin Nippert and Brandon Medders are in the running, but both are out of options, which would leave the team with little flexibility during the season. One possibility being discussed is trading or releasing one of the two and keeping Yusmeiro Petit or Jailen Peguero instead. Or the team could look to upgrade via the waiver wire which figures to be crowded this time of year.
"That flips around quite often to tell you the truth," Melvin said of what direction the team could go in. "There's been a lot of debate on that. Peguero has pitched well, Petit has pitched well, Nip hasn't pitched as well and he was the favorite going in. Medders has pitched well except for one outing. Options play into it, length and flexibility play into it."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.