Outfielder George Springer, the Astros' top prospect, has yet to play an inning in the major leagues. He almost certainly will not make the team's Opening Day roster. Yet last September, the Astros offered him a seven-year, $23 million contract, according to major-league sources. Springer, 24, rejected the offer, sources said, declining to give up three years of arbitration and one year of free agency. The obvious question: If Springer was good enough to be offered $23 million, why isn't he good enough to crack the 25-man roster of a team that has finished with the worst record in the majors in each of the past three seasons? Astros general manager Jeff Luhnow declined comment, adhering to his policy of discussing contracts only after they are completed. Springer, represented by the Legacy Sports Group, batted a combined .303 at Double A and Triple A last season with a .411 on-base percentage, .600 slugging percentage, 37 home runs and 45 stolen bases. A rival agent estimated that if Springer fulfills his potential, he will earn more than $30 million in his three arbitration years alone. In that sense, the Astros' offer of an unprecedented long-term deal was shrewd; they were gambling that Springer would sacrifice future earning power for an immediate life-changing guarantee. The Rays took a similar approach with third baseman Evan Longoria in April 2008, signing him to a six-year, $17.5 million contract after he had appeared in only six major-league games. And several player representatives believe the Astros' attempt to sign Springer will not be the last such effort by a team to lock up an elite prospect before he is established. The benefit to the player, besides financial security, is that he could head straight to the majors rather than face a delay as his team waits to start his service clock.