Tejada suffered the injury on a freak play in the top of the ninth inning. With one out, the Giants' Angel Pagan hit a pop-up to shallow left field, and both Tejada and left fielder Andrew Brown converged on the ball. Tejada made an acrobatic diving catch, but his right leg collided with Brown in the process.
"I was trying to go down low like we're taught, go down and try to get out of the way," Brown said. "He caught my leg.
"It makes me feel really horrible, to be honest with you. It's the last thing I wanted to do."
Mets manager Terry Collins and a team trainer ran onto the field to check on Tejada. He remained in the game for the final out of the frame but was lifted for a pinch hitter during the Mets' four-run rally in the ninth.
"I feel bad for Ruben, because he had something to really prove here in the last couple weeks," Collins said. "And now he's not gonna get that chance."
Tejada, 23, became the Mets' starting shortstop last season, after Jose Reyes signed with the Miami Marlins. He hit .289 in 114 games in 2012, and was the starter entering this season, as well. But after a sluggish start, Tejada was eventually optioned back to Triple-A Las Vegas, where he spent much of the season, before finally being called back up last week.
General manager Sandy Alderson questioned Tejada's work ethic earlier this year. It remains to be seen whether Tejada figures into the team's long-term plans.
Tejada finished the season batting .202 in the majors, with no home runs and 10 RBIs in 57 games.