Rookies can't succeed as backups: Myth or reality?

A lot of the discussion about the Pirates' recent acquisition of 38-year-old, 61-career-OPS+ John McDonald, and the increasing likelihood that 36-year-old, 83-career-OPS+ Brandon Inge will make the team, has centered on the notion that a player with little major league experience like Jordy Mercer or Ivan De Jesus, Jr., can't succeed as a bench player. Maybe very young Pirates' fans (all three of them) can be excused for thinking this, because the Pirates have had very few players of any sort make successful transitions from the minors to the majors for a long time. But there was a guy not all that long ago who set the Pirates' all-time pinch-hit HR record as a rookie who got only 183 plate appearances. The same year Craig Wilson set that record, Rob Mackowiak also began a very respectable career as a rookie utility player.

Of course, the other side of the equation here, which not everybody seems to want to acknowledge, is the Pirates' comically abysmal record with veteran bench players, but let's not discuss that now. It's too easy. Instead, let's look at the St. Louis Cardinals. I've had the sense for a long time that they've had quite a bit of success with rookies and AAAA players as bench players over the years, so I decided to check to see whether I was right. I started with the 2004 season because I felt like it.

2004

Hector Luna -- The Cardinals went with the 24-year-old Luna, who was a middling prospect, as a utility infielder. He managed a 73 OPS+ (12 points higher than McDonald's career mark), then returned in the role the next year and posted a 96 OPS+. In 2006, he posted a 99 OPS+ with the Cards until they traded him late in the season.

Yadier Molina -- The Cards brought the 21-year-old Molina up at the beginning of June and he backed up Mike Matheny the rest of the year. The lack of everyday playing time obviously wrecked his career prospects.

2005

John Rodriguez -- The 27-year-old Rodriguez was a AAAA type who'd never played in the majors before. As a backup outfielder and pinch hitter, he posted a 114 OPS+ that year and 108 in 2006, then never played in the majors again.

2006

Chris Duncan -- The 25-year-old Duncan, who'd never been considered a top prospect, hit 22 HRs and slugged .589 as a platoon/4th outfielder. He hit another 21 the next year in a similar role. (Luna and Rodriguez continued in their backup roles that year.)

2007

Skip Schumaker -- Schumaker was Alex Presley before there was an Alex Presley. He got his first significant MLB playing time as a 4th outfielder in 2007 at age 27. He posted a 111 OPS+ in 188 plate appearances spread over 88 games before becoming a regular the next year.

Ryan Ludwick -- By this time Ludwick was 27 and had been written off as a AAAA player by other teams. The Cards brought him up at the beginning of May and he started about half their games the rest of the season. He posted a 110 OPS+, then hit 37 HRs the next year.

Brendan Ryan -- The 25-year-old Ryan came up at the beginning of June to serve as a utility player. He played very little for about a month and a half, but started playing more later. He posted a 95 OPS+; it wasn't until later that he became a great-glove, no-bat shortstop. He continued in the utility role for one more year before becoming a starter.

2008

Brian Barton -- The Cards kept Rule 5 pick Barton all year and he put up a 98 OPS+ with a good .354 OBP in 179 plate appearances.

Joe Mather -- The Cards' other backup outfielder, the 25-year-old Mather, was also a rookie. He put up a 103 OPS+ in 147 plate appearances.

2009

Tyler Greene -- Greene served as a utility infielder as a 25-year-old rookie. He actually hit worse than John McDonald's career OPS+, but only by three points. He stayed in the utility role for three more years and his OPS+ ranged from 71-82, until the Cards traded him to Houston during the 2012 season.

2010

John Jay -- The Cards brought Jay up in late April and he served mostly as a pinch hitter for over a month. After going back to AAA for a bit, he returned and won a semi-regular role.

2011

Daniel Descalso -- Descalso started his rookie season in a utility role, but played regularly from late April until mid-season, and for some stretches after that, due to injuries.

2012

Matt Carpenter -- Carpenter started his rookie season in a corner utility role, but ended up playing regularly for long stretches due to injuries.

Shane Robinson -- As a 27-year-old rookie, Robinson served mainly as a pinch hitter. He managed an OPS+ of 83 (Inge's career mark) in 181 plate appearances.

So there you have it. The National League's best-run team has repeatedly placed players with little or no MLB experience in bench roles, often with excellent, and almost always with at least decent, results. But why follow their lead when you've had so much success with veteran backups?