Knowing the Pirates were starting right-hander Ian Snell, Diaz knew there was at least a chance that he'd be on the bench.
That's how it had been the previous two years, and based on the strong impression the left-handed-hitting Gregor Blanco has made over the past month, Diaz knew there wasn't any reason to take anything for granted.
"I looked [at the lineup] first thing when I came in today," said Diaz, who has hit .330 while being utilized in a platoon role with the Braves the past two seasons.
After he proved himself during the 2006 season, Diaz began platooning with Ryan Langerhans. Last season, the same platoon partners were used until Willie Harris replaced Langerhans.
Without much argument, it's easy to declare Blanco, who hit .282 with Triple-A Richmond last year, is more talented both offensively and defensively than both Langerhans and Harris.
"He can play all three positions, hit lefties and righties, steal bases," Braves hitting coach Terry Pendleton said. "He can do all of those things and that's a big plus."
If manager Bobby Cox ends up opting to used a platoon in left field again, Diaz isn't going to complain. He knows that this arrangement has allowed him to establish himself as a legitimate Major Leaguer.
"It seems like I'm going to get to play and that's always fun," Diaz said. "The more you get to play, the more fun you're going to get to have."
While hitting .318 against right-handers last year, Diaz proved to himself once again that his success isn't limited to when he gets to face lefties, who are currently giving him the most problems.
During his 0-for-3 Opening Night performance against the Nationals on Sunday, Diaz said he felt most comfortable against right-handed reliever Saul Rivera, who was throwing a regular supply of cut fastballs.
"I feel just as confident against righties as I do against lefties," Diaz said. "I've done it my entire life. There were very few lefties in Little League and all the way through the Minors."
Mark Bowman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.