CHICAGO -- Cubs Minor League pitcher Yomar Morel received a 50-game suspension after he was found in violation of the Major League Baseball Drug Prevention and Treatment Program.

The Office of the Commissioner of Baseball announced the suspension on Friday. Morel, 17, a right-hander, received the suspension after testing positive for a metabolite of Boldenone.

The suspension is effective immediately. Morel was on the roster of the Cubs' Dominican Summer League affiliate.

Marmol loses closer's job for time being

CHICAGO -- For the second straight game, Carlos Marmol was unable to convert a save situation and protect a two-run lead. Cubs manager Mike Quade said the right-hander will take some time to work on his mechanics and has lost his job as the closer for now.

"Hopefully when I get back, I'll be the old Marmol," he said.

Quade met with Marmol, pitching coach Mark Riggins and others, including pitchers Kerry Wood and Sean Marshall, prior to Friday's game against the Marlins, which the Cubs won, 2-1. Quade wanted to make sure Wood and Marshall were prepared to close Friday, if needed. The switch was prompted by Thursday's outing, during which Marmol didn't retire a batter in the ninth, walking four and giving up a hit. All five baserunners scored in Florida's 6-3 comeback win.

"There's mechanical work to be done when you go through a situation like this," Quade said. "The last time I saw him really, really sharp was against the White Sox. We need to talk about that and see where we're at today."

That Interleague game against the White Sox was July 3, and it was the last time Marmol struck anyone out. In six outings since, he's walked seven, given up five hits and eight runs.

Quade called on Marmol in the ninth Friday to protect a 2-0 lead, but he walked the first batter he faced on four pitches. He retired the next, then gave up a single to Hanley Ramirez, who was thrown out at second trying to stretch his hit into a double. Logan Morrison then hit an RBI single, and Marshall came in to get the final out for his second save.

Marmol asked Quade for a chance to pitch Friday and said he felt better on the mound.

"I appreciate what he did," Marmol said. "It's tough. I've got to keep working, and hopefully I can get better."

He'll get that chance to work on getting better in the next few days. There's no timetable for Marmol's return.

"Relievers just don't have the side time and the time to work on stuff that starters do," Quade said. "You almost have to say you're going to give him a couple of days."

It's not automatic that Marmol will be the closer when he does return, Quade said.

"Marshall has obviously been our most reliable guy," Quade said. "I have no problem closing with [Wood]. Circumstances will dictate some of that, but those two guys will be prominent late."

It's been a rough stretch for Marmol since that White Sox game. On July 4, he entered in the 10th with a runner at second and one out. The runner, Jayson Werth, stole third and then scored on a wild pitch by Marmol to give the Nationals a 5-4 win.

Marmol rebounded three days later on July 7 and threw one inning for a save. But on July 8, he gave up two runs on two hits, including a homer, in one-third of an inning against the Pirates. The next day, he picked up a save. Next was Thursday's mess.

This month, Marmol has a 16.63 ERA, giving up eight runs over 4 1/3 innings. In June, he had a 0.60 ERA, serving up one earned run over 15 innings in 13 games.

"He needs to get himself consistent, work-wise and understand what he needs to do, like he has for years," Quade said. "Everybody goes through tough times and adjustments and this is one of his. We don't want to lose sight of the fact that this guy has been good for a long time. It's not like he's been falling apart."

Cubs catcher Geovany Soto has seen Marmol fix himself in a game.

"For him, he falls into rhythms," Soto said. "He could walk a couple people and then he finds that slot and turns it on."

Marmol did his same pregame routine on Friday, going for a run with veteran Ramon Ortiz.

"Everybody is entitled to have a bad day," Soto said. "It's part of the job. Marmol is one of the guys who has a short memory and he's going after it. He's very professional in his job. He comes in, does his routine every day -- good or bad -- and sticks with it. He finds that [arm] slot, and it's over."

Bush signs Minor League deal with Cubs

CHICAGO -- The Cubs have tried to bolster their pitching this season by adding veterans Doug Davis, Braden Looper, Todd Wellemeyer, Rodrigo Lopez and Ramon Ortiz. On Friday, they signed veteran right-hander Dave Bush to a Minor League contract, and he will report to Triple-A Iowa.

Bush, 31, was 0-1 with a 5.79 ERA in 17 games this year with the Rangers, including three starts. In 37 1/3 innings, he gave up 47 hits, walked nine and struck out 23. Texas released him on July 6.

The right-hander has pitched for the Blue Jays, Brewers and Rangers and is 56-69 with a 4.70 ERA in his career. He did post back-to-back 12-win seasons in 2006 and '07 with the Brewers.

His last outing this year was June 30, when he pitched one inning in relief against the Astros, giving up two runs on three hits.

Looper and Wellemeyer were with the Cubs in Spring Training and never made it to the big league team this season. They both have retired. Davis went 1-7 with a 6.50 ERA in nine starts before being released. Lopez and Ortiz are still on the active roster. Lopez (1-2, 4.02 ERA) will start Monday, while Ortiz (0-2, 7.20 ERA) was expected to go to the bullpen.

Jackson motivated after promotion to Triple-A

CHICAGO -- Brett Jackson, the Cubs' No. 1 pick in the 2009 First-Year Player Draft, and Ryan Flaherty, a second-round pick in 2008, were both promoted from Double-A Tennessee to Triple-A Iowa on the same day. So the two drove in Flaherty's car from Tennessee to Iowa and had plenty of time on their 14-hour trip to discuss a variety of topics.

They're now one step away from the big leagues.

"You can taste it now," Jackson told the Des Moines Register. "You can really smell it. It motivates me more. I'm very thankful to be here and excited about the opportunity to play in Iowa."

In his first game with the Iowa Cubs on Thursday, Jackson hit a double. He batted .256 at Tennessee, and spent time on the DL because of a strained ligament in his left pinkie finger.

"In the long run, I think it will be useful, learning to adjust after an injury and going through a couple of slumps," Jackson said. "Certainly, I'd rather be hitting .300. But all things considered, I'm happy with how the season has gone."

Extra bases

• All-Star Starlin Castro is quickly closing in on his 2010 numbers. The shortstop, who was the Cubs' lone representative at the All-Star Game, entered Friday's game with 49 runs in 90 games; he totaled 53 runs in 125 games last season.

Castro, 21, also has 39 RBIs; he drove in 41 in his first season in the big leagues. He has 34 extra-base hits, five shy of his total of 39 in 2010. Castro ranks fourth in the Major Leagues with 117 hits.

• First-base coach Bobby Dernier will miss Friday and Saturday's games to attend his son Derek's wedding. Dave Keller, a special assistant on manager Mike Quade's staff, will take over as first-base coach.