Gwaltney was hoping to be healthy in time to join a full-season club by some time in July. Instead, he believes he may have come back a bit too early.
"I was throwing in games about a month ago down here and my shoulder got really sore. I had to back off for a couple of weeks," the pitcher said. "I don't think my arm was quite ready to handle all the up's and down's."
Gwaltney is throwing off the mound again, but both he and the Cubs have agreed to look more toward 2007 rather than the remainder of '06.
"We're trying to make sure everything feels good and is sound," Cubs Farm Director Oneri Fleita said. "We're looking more toward 2007 and will be happy to know that he's healthy by then. But he'll get some more innings in here just so he can get some more confidence and feel good about himself."
Gwaltney signed with the Cubs as a minor league free agent last year.
Born in Germany, and with residence all over the world even before he signed a professional baseball contract, Gwaltney was 4-1 with a 2.56 ERA in 10 starts with Class-A Peoria a season ago before moving on up to High-A Daytona and appearing in 22 games – 17 from the bullpen.
"The coaches all agreed that my mechanics look pretty much the same as they did before the surgery, so I think they're pretty happy with that," Gwaltney said. "I'm throwing my pitches (slider and changeup) with the same strength and velocity as before."