The platoon role is a departure from the everyday playing time that Jones had enjoyed since he made his Pirates debut in July 2009. But with Jones' prolonged struggles against left-handed pitching last season, the Pirates felt that they needed a right-handed hitter to complement him. The club got that by signing Diaz.
The decrease in playing time is likely to be a disappointment for Jones, who vowed near the end of the season to spend the winter rediscovering the swing that made him so successful in 2009. Jones admitted that the favorable right-field dimensions at PNC Park enticed him to get too pull happy with his swing last season. That, Jones believes, was a large contributor to his offensive woes during the second half.
It also explains why -- in a park that should favor hitting from the left side -- Jones batted just .228 at home in 2010. Eleven of his 21 home runs came at PNC Park, but his .265 road average was much more impressive.
In an effort to avoid the temptation to aim for the Clemente Wall, Jones is spending the offseason shortening up his swing. This should put him in position to do a better job of hitting up the middle and using left field. Simplifying the mechanics of his swing, Jones added, will be key, too.
"I'm going to make my swing sound and short so that I can get back in the swing of things when I do get into a funk," Jones said. "When I did get in a funk swinging the bat, I wasn't able to get out of it quick. You start thinking about your swing and thinking about taking a good swing, and you lose that aggression to go up there and just see the ball and attack it. That definitely hindered me a lot, too."
It might be too late for Jones to prove that he can hit left-handers, but the Pirates need Jones to be a key piece of the offense against right-handed pitching. He hit .262 and connected for 15 of his 21 homers last season against right-handers.
The year before, Jones batted .333 against right-handers, while he hit for just a .208 average against southpaws.
Though manager Clint Hurdle has stayed mum about his lineup plans, it seems natural that Jones will shift down into the fifth or sixth spot when he is in the starting lineup. The fact that Jones won't be the team's most prolific middle-of-the-order bat anymore should also help him to relax some.
"I need to control those downtimes and just get back to where I was when I was having success," Jones said. "I just need to make sure I don't think too much. I need to simplify things and that will keep me more successful throughout the year.
"I know my age is a little older, but it was also my first full season in the big leagues. I'm still young there. I learned a lot this year. I'm going to take it in stride and work hard and just make myself the most prepared that I can be."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.