The sky was the limit for Grady Sizemore.

Eleven years ago today on April 18, 2009, Sizemore doubled and homered as part of a 14-run second-inning stampede, helping the Indians romp to a 22-4 victory in just the third game at the new Yankee Stadium. At that point, the future could not have looked brighter for one of the game’s most talented young stars.

Sizemore was 26 years old and already a three-time All-Star and two-time Gold Glove Award-winning center fielder, who had been one of the four most valuable players in the sport for the past four years. That big performance in the Bronx left him with a .275/.383/.608 slash line with four homers and 11 RBIs in his first dozen games of 2009 -- seemingly setting the stage for another campaign worthy of an MVP candidate.

Nobody could have known how quickly or completely things would fall apart.

Barely more than a decade later, Sizemore’s ultimate career path remains difficult to swallow. He’s the same age (37) as Robinson Canó, was drafted out of high school the same year (2000) as Yadier Molina and was part of the same rookie class (‘04) as Zack Greinke. Had he held up physically, he might now be putting the finishing touches on a Hall of Fame career

It wasn’t to be. But on this anniversary of what appears in retrospect to be the zenith of Sizemore’s all-too-brief career, it’s worth looking back at what was, and what might have been.

A generational talent

Sizemore oozed athletic ability, enough so that he was headed toward both playing baseball and quarterback at the University of Washington before the Montreal Expos selected him in the third round of the 2000 Draft and gave him a large enough bonus to turn pro. Rick Neuheisel, Washington’s Rose Bowl-winning football coach at the time, later told Sports Illustrated of Sizemore, “If he’d been a track guy, he’d have been a decathlete.”

Traded to Cleveland along with Cliff Lee, Brandon Phillips and Lee Stevens in a momentous deal for Bartolo Colon in June 2002, Sizemore’s development accelerated. By the end of July ‘04, just shy of his 22nd birthday, he was in the big leagues.

What followed was a four-season burst that few players in Major League history could replicate. Sizemore played nearly every day from 2005-08. He got on base (.372 OBP), showed 20-30 homer power (.496 SLG), was an elite baserunner (115 steals) and played at least a solid (and thrilling) center field. Put it all together, and Albert Pujols, Chase Utley and Alex Rodriguez were the only hitters to accrue more WAR during that time.

This sensational stretch placed Sizemore in prestigious company. Through 2008, his four-year FanGraphs WAR of 27.3 from ages 22-25 ranked in the top 20 in modern history for a position player, essentially even with Stan Musial and Barry Bonds, and just ahead of Willie Mays. Or, to compare Sizemore with a contemporary outfielder, consider this:

Grady Sizemore, ages 22-25 (2005-08)
2,950 PA, .372 OBP, .496 SLG, 129 wRC+, 107 HR, 115 SB, 27.3 fWAR

Mookie Betts, ages 22-25 (2015-18)
2,710 PA, .370 OBP, .524 SLG, 135 wRC+, 105 HR, 103 SB, 28.8 fWAR

Sizemore’s most similar players by age during that time, per Baseball-Reference’s calculations? Hall of Famer Duke Snider, Betts and Bonds.

Amid all that, Sizemore found himself on the cover of Sports Illustrated for the May 14, 2007, edition, staring out at the world over eyeblack, with a black bat curled behind him in a follow-through pose. The quote below the headline, from then-Indians general manager Mark Shapiro proclaimed, “He’s without a doubt one of the greatest players of our generation.”

That was only the beginning of the praise heaped upon Sizemore in Tom Verducci’s cover story, which delved into both Sizemore’s quiet, focused demeanor and brash talent. Rival American League Central manager Ozzie Guillen referred to Sizemore as “the best player in our league” and “Superman.” Shapiro said Sizemore would have been in the NFL if not for baseball and labeled his breakout as a “once-a-decade convergence of effort, energy, talent, athleticism and baseball ability.” Sizemore, he said, would have been Derek Jeter had he played in New York.

It’s easy to cringe at those comments today, or view them as hubris. But Sizemore was backing them up -- until his body cruelly betrayed him.

The breakdown

Even as Sizemore lit up Yankees pitching 11 years ago today, things may already have been unraveling. Earlier that spring, he had pulled out of the World Baseball Classic with what was described at the time as a sore groin. Nonetheless, Sizemore was in the lineup on Opening Day, starting each of the team’s first 28 games, and 49 of its first 51. But he wasn’t right.

After the big day in the Bronx, Sizemore slashed a mere .206/.283/.355 through the end of May before the Indians placed him on the injured list. He was out for only a few weeks and performed more like his usual self at the plate in 57 games after returning, but Cleveland shut him down in early September and announced that he needed two surgeries: one on his left elbow and one related to the earlier groin problem. The issues had been bothering Sizemore all year, but he prided himself on staying in the lineup.

"I knew going into the season it was going to be a tough year," he said at the time. "You'd like to be injury-free. I knew it was going to be a battle."

Still, the surgeries seemed like a temporary setback, with little reason for long-term concern. Sizmore was, “entering his theoretical peak age-27 season,” as the following year’s Baseball Prospectus annual guide put it. “If he can stay healthy, all indications are that he will return to form in 2010.”

Instead, the pain was just beginning. There was another abdominal surgery, a back surgery and three knee surgeries, including microfracture procedures on both knees, subjecting Sizemore to months upon months of grueling physical rehab, not to mention mental anguish.

“You just didn't get a lot of answers," Sizemore told ESPN in 2014, looking back at years of unsatisfying doctor visits. "That was the hard part."

He played just 104 roughly replacement-level games for the Indians in 2010-11, then missed two entire seasons before making it back as Boston’s Opening Day center fielder in ‘14.

It was a great story, and Sizemore’s days on the injured list were over. But he also was 31, five years removed from being a productive big leaguer, and worn down by the relentless setbacks. While there were flashes of the old Sizemore here and there, he hit .242/.303/.366 with a negative WAR in 677 plate appearances for the Red Sox, Phillies and Rays from 2014-15, playing his final game at age 33.

Looking back

Sizemore sits in the middle of a group of 19 modern position players to produce between 25-30 fWAR from the ages of 22-25. Setting aside Betts, who is only through his age-26 season, the other 18 players had a median WAR of about 50 over the rest of their careers. Ten are in the Hall of Fame, and that doesn't even include Bonds or Rodriguez. Sizemore is the only one who didn’t clear at least 20 WAR from age 26 onward, and it wasn’t close.

Perhaps Sizemore, whose speed and defense in center were integral to his value, was destined for an early decline no matter what. But it’s hard not to feel that he, the Indians and baseball fans everywhere were robbed of a memorable, perhaps even Cooperstown-worthy career.

Those first four full seasons will remain an impressive achievement. The rest? One of recent baseball history’s great what-ifs.