Pena, who signed a one-year, $10 million contract with the Cubs on Wednesday, is coming off a season in which he hit 28 homers and drove in 84 runs. That's the good news. The bad news is that he also batted a career-low .196 and struck out 158 times.
"When you strike out that much, it means you're not getting pitch recognition and you're not swinging at the right pitches," Jaramillo said Wednesday from his Texas home.
Teams would often employ a defensive shift during Pena's at-bats. Jaramillo said the problem may have been that Pena was trying to beat the shift too much, which also could have contributed to his low average.
The two were together with the Rangers. Pena was the team's first-round pick in the 1998 First-Year Player Draft, and learned Jaramillo's system when he played for Texas in the Minors for four years before he was promoted to the big leagues in September 2001. He appeared in only 22 games that month and was included in a five-player swap with the Athletics.
"It's been so long, but you never forget certain kids," Jaramillo said of Pena. "He's got the athleticism and he's got the desire -- that's what you look for."
There's mutual respect.
"Everyone knows how good of a hitting coach he is -- it's no secret," Pena said of Jaramillo, who is coming off his first season with the Cubs. "I know him personally and know what he's all about. He's a very positive man, and even if he didn't teach you anything about hitting, just to be around him will make you better because of the attitude he has. You add all the knowledge he has, and it is definitely very attractive to me."
Jaramillo and Cubs general manager Jim Hendry discussed Pena's attributes during the team's organizational meetings in November. The free-agent first baseman seemed like a perfect match for the Cubs.
"He's a '10' human being and teammate, and it really was a great fit," Hendry said.
Pena called Jaramillo shortly after he signed his deal with the Cubs at the Walt Disney World Swan and Dolphin Hotel. Jaramillo said Pena was eager to get started.
"I think he'll make everybody better," Jaramillo said.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat This story was not subject to the approval of Major League Baseball or its clubs.