While he primarily stuck with fastballs during his 25-to-30 pitches before Friday's game, the White Sox valuable setup man reported progress.
"We are moving forward," said Linebrink, who said the focus wasn't as much on location as it was on how the baseball was coming out of his hand. "You have to look at it over the past couple of weeks. There are some good days, and some not as good days. But overall, we are progressing."
Linebrink follows the plan of throwing one day, followed by a day off, and then back to throwing again the next day. He had originally hoped for a return by mid-August, but Linebrink said on Friday it's looking more like the end of the month or beginning of September.
Of greatest importance to the veteran is that he has been examined by a number of doctors and had two MRIs, all of which have shown nothing major structurally wrong with his shoulder. Whatever the exact issue is concerning the shoulder, more harm is not being done by working through the pain.
"I'm really trying to put as much effort into it as I can," said Linebrink of his bullpens. "I'm not going out and grunting like I would in a game. But I'm doing as much as I can, what my body will allow. It's something that we have to start testing it and break through stuff. There are times when it is uncomfortable, but I have to push that to the backburner and work through it.
"You go through periods of doubt and frustration, but you need to be patient. I would like for nothing more than to have been pain free two or three weeks ago and throwing bullpens and getting ready to go to rehab or get back in the game.
"It hasn't really worked for us that way," Linebrink added. "But I think if you look at the span of when we started playing catch, I've noticed improvement."
Scott Merkin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.