OAKLAND -- As the days flip on the calendar it is starting to look less and less likely that Jordan Norberto will return to the Oakland Athletics bullpen before season's end. Norberto was placed on the disabled list with left shoulder tendonitis on Aug. 21 and has been out since Aug. 17. It is his second DL stint this season with issues in his throwing shoulder.Norberto, 25, hopes to begin playing catch soon. The team can't make any estimates on a potential return date until he picks up a ball and throws. "My arm is making progress and when I am stretching now I am not feeling pain like I used to feel before," Norberto said. "We are going to start throwing this week, I feel a lot better.""We'll take it day to day with him once he starts throwing. I am not sure how long it would take to get him in game shape," A's manager Bob Melvin said. "We do feel like we have good depth in our bullpen, but man, he was a major contributor." Norberto says this injury is similar to the previous one. He missed 18 games with a left shoulder strain from May 31 to June 20. Yet, he has already missed 26 games during his latest DL stint. That may have to do with the cautious approach the A's are taking with him. "Now we have to be more careful because I don't want to be hurt again," Norberto said. "They want me to take care of it 100 percent before I come back." Norberto seemed to be fully recovered when he was activated from the DL on June 21; in 18 appearances he posted a 1.69 ERA. He emerged as a key component to the A's bullpen this season. In 39 games he had a 2.77 ERA, struck out 46 batters and walked 22 in 52 innings. Of those 39 appearances, 19 went for more than an inning. "If he doesn't pitch again he's already had a spectacular year for us," Melvin said. "He got righties out, he got lefties out, he gave us length, he pitched late in games, he could pick up a starter if he was struggling, he was as versatile as we have." Even without Norberto the A's bullpen has been one of the strengths of the team. A's relief pitchers rank first in the American League and second in the major leagues with a 2.80 ERA. Forced to sit back and watch, Norberto likes what he sees in his teammates' performances. "They've been doing a really good job in the bullpen," Norberto said. "They pick each other up like Jerry Blevins the other night coming in for Grant Balfour and getting a save, Ryan Cook made an adjustment and he's been very consistent. Sean Doolittle too, Pat Neshek, all those guys, they pitch really well."