Romero and a few other Toronto rookies were mere hours away from the first Opening Day of their careers.
"You get the chills when you walk out there on that field and you're out there by yourself," said Romero, sitting in front of his new locker inside Toronto's clubhouse. "It's a feeling you can't even explain. I can't put into words how excited I am."
The Blue Jays enter this season with a handful of players light on big league experience with key jobs on the roster.
Romero earned the fourth starter's job this spring, and fellow rookie Scott Richmond enters the year as the fifth man in the rotation. David Purcey, while no longer technically a rookie, has been slotted into the second slot behind ace Roy Halladay. In left field, Toronto has decided to hand the everyday duties to 21-year-old Travis Snider -- the club's top prospect.
For all four players, Monday's game against Detroit marks the first time they will stand along the third-base line under the dome in Toronto and hear their names echo through the stadium as members of an Opening Day roster. It's a moment that will undoubtedly stick with the players for the rest of their lives.
"Just to go out there and have a packed house, it'll be special," Richmond said with a smile. "To be here with the Blue Jays and coming back here, it's going to be a great day and I'm looking forward to it. It's something I'll always remember."
The evening has an added element for Richmond -- a native of North Vancouver, British Columbia -- considering the long path he took to the Majors and how his spring went for the Jays. Richmond is a rookie at 29 -- signed as a non-drafted free agent out of the independent league two offseasons ago -- and was given a chance to win a rotation job during Spring Training.
Richmond left Florida in March to pitch for Team Canada in the World Baseball Classic, but didn't receive an opportunity to take the mound due to the team's quick elimination. When he returned to camp, Richmond was behind the other pitchers and he finished the spring with a 6.63 ERA over five Grapefruit League outings.
Needless to say, Richmond never felt he was a lock to make the Opening Day squad.
"There were eight starters in camp and I left and then didn't pitch," Richmond said. "It was just kind of a weird spring for me. The numbers that I had just weren't numbers that I was satisfied with. Now that I'm here, I take that as a blessing that the organization has faith in me. I plan on proving that they made the right decision."
It was a similar situation for the 24-year-old Romero, who was selected by the Jays in the first round of the 2005 First-Year Player Draft.
Romero struggled early in the spring and was considered a long shot to even be in the discussion for a rotation job. The left-hander worked with pitching coach Brad Arnsberg on adjusting his delivery mechanics and he ended the spring on a high note, finishing with a 3.91 ERA in six spring outings and convincing the club to hand him a big league job.
Romero is scheduled to face the Tigers in his Major League debut on Thursday.
"The one thing that's on my mind is that I've got to stay humble every time I'm out there," Romero said. "I've got to take it day by day. I can't look forward to the future or look at the past. It's just moving forward every day and I'm just excited to be here, and I'm going to continue to work hard and continue to do what got me here.
"It's exciting. This is something you dream of, especially Opening Day. All my friends back home, everyone's like, 'Do you realize you're there for Opening Day?' Yeah. It's starting to sink in a little and it's exciting."
It's a little different for Snider.
Snider joined the Jays last August and finished the season with the club, hitting at a .301 clip over 24 games with Toronto. This spring, all Snider did was hit .381 with four home runs and 10 RBIs in 63 at-bats, forcing his way into a regular role with the club.
While Snider is excited to experience his first Opening Day, he said he hasn't felt any pregame rookie jitters. Being around the Jays for as long as he has already has helped.
"I feel good. I'm excited. Nerves don't really come into play right now," Snider said. "Between the month [with the Jays last year] and then spending the two months down in Spring Training with the guys, you get to fit in more. That comfort level is a little bit higher and you really just go out there and focus on playing."
Jordan Bastian is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.