Sergio Romo has spent a lifetime proving doubters wrong. Those days are not over, even after he pitched in 10 of the Giants' 16 postseason games in 2012, saved three of their four World Series wins and froze Detroit's Miguel Cabrera with a surprise fastball to set off the celebration.

Despite that on his resume, Romo still has to prove to his own employers that he is durable enough to take on a closer's workload, which can be heavy for a team that plays as many close games as the Giants do.

Manager Bruce Bochy knows Romo has the guts and the stuff for the job. Who could argue otherwise? Moreover, Bochy said Friday that Romo will be his Opening Day closer and get the "lion's share" of save opportunities because "he's earned the right to be out there, just the way he threw the ball at the end last year."

However, Bochy qualified his statement, saying, "At the same time, we'd like to watch his workload to make sure we keep him healthy."

General manager Brian Sabean said the concern is Romo pitching several nights in a row, or maybe five times in a week, which Romo has not been asked to do. True, he carried a big load in the postseason, but the Giants knew a long rest was near.