DENVER -- Cubs reliever John Grabow threw off the mound Friday for the second time, throwing 15 pitches, and said he was making progress in his rehab from a strained left knee.
Grabow threw fastballs and sliders during his session at Coors Field.
He's been on the disabled list since June 29.
"He's been slowly getting better," Lou Piniella said.
Howry released to clear spot for Zambrano
DENVER -- The Cubs gave Bob Howry his unconditional release on Friday to make room on the roster for Carlos Zambrano and the right-handed reliever was expected to retire.
Howry, who turns 37 on Aug. 4, was 1-3 with a 7.71 ERA in 38 games with the Cubs and D-backs this year, and 0-3 with a 5.66 ERA in 24 relief appearances in Chicago. He had scuffled in July, posting a 12.46 ERA in 10 games. He gave up 12 earned runs on 19 hits over 8 2/3 innings this month.
"That was a little hard on me because he's such a classy, classy young man," Lou Piniella said of the 13-year veteran. "We've made a commitment to our young pitchers here. I think Bob is going to retire -- that's the indication I had."
Piniella, Howry and pitching coach Larry Rothschild met in Piniella's hotel room on Friday morning.
"It was a little difficult," Piniella said. "I'm not entirely sure he was surprised. I wish him well. He's a good person and he's had a heck of a career."
Howry was released by the D-backs on May 17 and signed with the Cubs on May 21 for his second stint with the team. He also pitched for the Cubs in 2006-08.
"When I was a rookie, Bob helped the guys learn the ropes," Cubs reliever Sean Marshall said. "He's a veteran and it rubs off the way he carries himself every day. He worked hard. It just didn't work out for him.
"I don't know what he's going to do now, but I know when I first came up, he helped me out and kept me in line," Marshall said. "He was kind of like the sheriff around here. It's always good to have a veteran around here to learn from."
Zambrano, who was the Cubs' Opening Day starter, was assigned to the bullpen and joins closer Carlos Marmol, Marshall and rookies Justin Berg, Andrew Cashner, James Russell and Brian Schlitter.
Piniella to miss time to attend uncle's funeral
DENVER -- Cubs manager Lou Piniella will fly back to Tampa, Fla., on Saturday and miss three games so he can attend the funeral of his uncle, Joseph Magadan, who is former big league infielder Dave Magadan's father.
Joseph Magadan was 92 and passed away Thursday. He was Piniella's mother's brother and was very close to the Cubs manager.
Bench coach Alan Trammell will be the Cubs interim manager and special assistant Matt Sinatro will take over as bench coach for the three games, Saturday, Sunday and Monday at Wrigley Field when the Cubs open a three-game series against the Milwaukee Brewers.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.