Cubs pitchers Lackey (shoulder), Rondon (triceps) put on DL

DENVER – With a focus on October, the Cubs have shut down two of the pitchers who figure prominently in their playoff plans this year — putting both John Lackey and Hector Rondon on the disabled list Friday.

The best record and largest division lead in baseball allow the Cubs the luxury of moves they said were more precautionary than imperative as they opened a grueling nine-game road trip out west starting Friday night in Colorado.

“Where we’re at record-wise makes it easier, but it’s still the right thing to do, regardless,” manager Joe Maddon said. “If you have guys that need time to get well, you still have to give them time to get well, and you don’t want to push that because it can only be a big negative on the backside.”

Both had MRIs Thursday after symptoms persisted in Lackey’s shoulder and Rondon’s triceps.

Lackey, who was signed to a two-year deal last winter in large part because of his postseason pedigree, was diagnosed with a strained shoulder after soreness experienced in his start Sunday continued when he tried to throw on the side during the week.

Rondon, who went from one of the top closers in the league to one of its top setup men with last month’s acquisition of Aroldis Chapman, missed a week, then returned and experienced tightness after appearances Sunday and Tuesday. He also was diagnosed with a strain.

“For me it’s no big deal because I’ve been pitching like that for a couple games, and it doesn’t feel like that much pain,” said Rondon, who won’t be allowed to pick up a baseball for close to a week before starting throwing program. “But I know I have something there I have to take care of.”

Maddon said if the Cubs were playing games with more at stake later in the season or in the postseason, Rondon would continue to pitch through the issue.

One big-picture byproduct of the more immediate-future moves is that left-hander Rob Zastryzny becomes the first pitcher in five Cubs drafts under president Theo Epstein to pitch for the big-league club.

Only one other has made it to the big leagues: Zack Godley, the Diamondbacks pitcher who was a Class A player traded in the Miguel Montero deal.

“It’s an honor to be the first one,” said Zastryzny, who was first told of the distinction by his dad, who saw it on Twitter. “And now I’m going to go out there every day and prove why was the first one.”

Zastryzny, a second-round draft pick from Missouri in 2013, was 10-5 with a 4.31 ERA combined at AA and AAA this year. Right-hander Felix Pena (3.41 ERA in 63 games for AAA Iowa) also was called up for a big-league debut Friday.

Both were added to a bullpen that now included three rookies (also Carl Edwards Jr.) plus another (Spencer Patton) who hasn’t pitched a full season in the majors.

Rondon goes on the DL exactly a week after the Cubs’ No. 2 setup man, Pedro Strop, underwent arthroscopic knee surgery (expected to miss at least another month).

“I like it. Sometimes you catch lightning in a bottle,” said Maddon, who as a coach in Anaheim in 2002 when Francisco Rodriguez debuted and became a postseason hero, and a manager in Tampa Bay in 2008 when David Price was a late-season factor for another World Series team.

“You never know,” he said. “These are the kind of moments when a guy can really catapult his career, too.”

What is known: The Cubs are crossing their fingers on the full health next month of Lackey, who has started two World Series-clinching victories for two different teams.

“He gets it,” Maddon said of the often cantankerous Lackey, who didn’t fight the DL move. “It was one of the easier conversations we’ve had, surprisingly. I didn’t have to brace myself.

“I think he knew that it was the right thing to do.”