It did not take long for the tone to be set on splashy openings.
On April 5 -- Opening Day for most Major League teams -- Braves fans gathered at Turner Field to get their first look at Heyward.
In the bottom of the first, Heyward swung the bat for the first time in his career and smashed a 414-foot, three-run homer to right-center against Cubs righty Carlos Zambrano.
Imagine the joy of Eugene Heyward, Jason's father, as he took in the overwhelming scene.
"We went crazy," Eugene Heyward said that day. "We were all hugging, high-fiving and going crazy. I didn't actually see it. We were being mobbed by each other. We were knocking each other's hats and glasses off. We just saw the ball go out and after that we just erupted. It was unbelievable."
One month later -- May 7 to be exact -- a 20-year-old shortstop named Starlin Castro had a similar introduction to Major League pitching, smashing a three-run homer in his first career-at bat. Later in the game, which was played in Cincinnati, Castro roped a three-run triple. Not bad for a prospect who was summoned straight from Double-A.
In a 14-7 win for the Cubs, Castro, who hails from the Dominican Republic, became the first player in Major League history to have six RBIs in his debut.
"I didn't believe it," said Castro. "I never expected to hit a home run in my first at-bat."
Perhaps he should have. In 2010, such an entrance seemed par for the course.
Take the case of Nava. Though Red Sox Nation is one of the most passionate fan bases around, Nava had been all but anonymous until June 12.
In a roster move before that day's game against the Phillies, the Red Sox sent prospect Josh Reddick back to Triple-A Pawtucket so he could get more regular at-bats. That opened up a roster spot for Nava, a former independent leaguer the Red Sox acquired from the Chico Outlaws back in 2007 for the initial acquisition cost of $1.
Nava, wearing No. 60, batted ninth for the Red Sox in his debut and got the start in left field. In his pregame interview with Nava, longtime Red Sox radio broadcaster Joe Castiglione playfully ended the chat by saying, "Hit the first one out."
So as the first pitch from Phillies righty Joe Blanton came across the plate, Nava belted it into Boston's bullpen in right-center for a grand slam in a game that was broadcast nationally by FOX. Kevin Kouzmanoff (Sept. 2, 2006) is the only other player to hit a grand slam on the first pitch of his Major League career.
The tale of Nava was surreal. He was only 70 pounds when he started high school and spent part of his college years as an equipment manager for the baseball team at Santa Clara University.
"He wasn't a prospect," said Don Nava, who was in the stands at Fenway Park with wife, Becky, to witness their son's magical moment. "He's never been a prospect. He washed uniforms for two years at Santa Clara. He's called me between the washer and the dryer. I say, 'What are you doing?' He says, 'I've got a pocket full of quarters. I'm going from the washer to the dryer.' The guy is getting kicked out of the laundromat on a Saturday night in Compton, Calif."
If the story of Nava is one that literally came out of nowhere, the one four days earlier involving Strasburg had been building for days, if not weeks. Yet even after all that hype, Strasburg somehow exceeded it in his June 8 debut for the Washington Nationals.
In a seven-inning clinic of power pitching, Strasburg fanned 14 batters and walked nobody. He gave up four hits and two runs, and a packed house of 40,315 at Nationals Park loved every minute of it. Strasburg would come just one punchout shy of the record in a debut, set by Karl Spooner in 1954 and tied by J.R. Richard in '71.
"I was just going to go out there and have fun," Strasburg said. "It's kind of amazing. It's kind of like when you get married and everything. You kind of want to go into it and really remember everything. Once it's done, you don't remember a single thing."
While the debut was the pinnacle of Strasburg's rookie year, his season-ending Tommy John surgery on Aug. 27 was the low point. Once his recovery is complete, the Nationals hope Strasburg will resume blowing away the competition.
No sooner had Strasburg underwent surgery than another flame-thrower came up to the Majors after weeks of anticipation.
Cuban defector Aroldis Chapman had been clocked at 105 mph in the Minor Leagues. The night the Reds called him up, the lefty swiftly got to show off his lightning bolt of an arm in front of the home crowd at Great American Ball Park.
In a bottom of the eighth inning that Reds fans will never forget, Chapman mowed down the side in order, striking out one and unleashing two pitches that were clocked at 102.
Chapman made 15 outings for the National League Central champion Reds down the stretch, striking out 19 over 13 1/3 innings.
There was yet one more debut to remember in 2010, and it happened in Toronto on Aug. 7. That was where Blue Jays catcher J.P. Arencibia -- the club's first selection in the 2007 First-Year Player Draft -- belted the first pitch of his career out of the park. His first MLB game consisted of four hits and two homers. Arencibia was the first player since 1900 to have four hits and two homers in his first Major League game, and his heroics keyed a 17-11 win over the Rays.
"I could never have imagined this," Arencibia said. "I could never have imagined this -- ever."
And it's tough to imagine that any season in the near future will have a collection of individual debuts to rival 2010.