Guillermo Mota opened the 2012 season with the San Francisco Giants, pitching out of that club's bullpen.

This was nothing new for Mota. He's been pitching long enough to have been a Montreal Expo ... for three seasons.

After nine appearances this season, Mota was suspended for failing a drug test.

This was nothing new, either; because this was Mota's second suspension. After the 2006 season, he drew a 50-game suspension for failing a drug test, and served that suspension from the beginning of the 2007 season. Thus, this year Mota became one of the few players to be suspended twice for using performance-enhancing drugs.

This time around, Mota tested positive for Clenbuterol. Tuesday, while acknowledging that his first suspension did result from the intentional use of steroids, Mota maintains his latest suspension was due to an accident. From reporter John Shea (via SFGate.com):

Guillermo Mota answered questions from a few reporters in the Giants’ dugout moments ago and insisted his positive test — for Clenbuterol, a stimulant, which is used to treat asthma but also to build muscle and burn fat — resulted from children’s cough medicine.

"I did not read the label," he said. "It was a mistake."

It was Mota’s second offense, thus the 100 games. In 2007, he was suspended 50 games.

The first suspension was caused by steroid use?

"It was," he said.

Mota said MLB officials "believe me 100 percent" regarding the children’s medicine, and manager Bruce Bochy suggested the Giants are convinced of it.

These sorts of things can happen, and probably do. There's a pretty good reason why the players aren't interested in a permanent suspension for players who fail just one drug test. This is their livelihood, after all.

Anyway, Mota has served his 100-game suspension and the Giants have activated him, with Jeremy Affeld going on paternity leave. And with the rosters expanding in a few days, Mota figures to spend the season working out of the Giants' bullpen.