MASH Report (1/6/14) – Major Knee Injury Edition

Not much in injury news over the past week, so I decided to dive mainly into the effects of major knee injuries.

• The Mariners recently signed Corey Hart who missed all of 2013 after left knee surgery. I went through my injury database and found 60 outfielders who either tore or had surgery on a knee. Additionally, I added those outfielders who missed 90 days or more because of a knee issue. In all, I found 60 outfielders who met the criteria. I looked at the weighted average from the season before … to the season of the injury… to the season after the injury. Here are the results:

AVG
Season before to injury season: -0.019
Injury season to season after: +0.004
Season before to season after: -0.016

OBP
Season before to injury season:-0.018
Injury season to season after: +0.005
Season before to season after: -0.016

SLG
Season before to injury season: -0.050
Injury season to season after: +0.019
Season before to season after: -0.031

The hitters saw a significant drop in all three stats. The drop in OBP was completely driven by the decline in AVG.

One issue with the data is the players’ average age was 30-years-old. These hitters are on the decline and should expect some production drop. Using the Oliver aging values, the average declines from the season before the injury (29-years-old) to the season after the injury (31-years-old) are predicted to be:

Stat: Normal Decline
AVG:  -.005
OBP:  -.004
SLG:  -.014

The hitters definitely saw larger declines than expected because of their age. In 2012 Hart hit .270/.334/.507. These number are close to his career numbers, so they can be used as a measure of his talent level. His 2014 triple slash line projects to be .254/.318/.476 using the above values.

Additionally, here are his 2014 projections available at FanGraphs:

Steamer: .257/.325/.456
Oliver: .251/.322/.432

The AVG and OBP values are almost identical. Both projection systems have his SLG dropping even more than expected. I guess the additional drop is probably because Seattle signed him.

• I wouldn’t be worried about Bryce Harper’s comments to “get as big as a house”. He has lost muscle over his first two seasons and he just wants to start the season as big as possible. In each of his first two seasons, his production has dropped in the 2nd half.

Season: 1st Half wOBA, 2nd Half wOBA
2012: .358, .348
2013: .383, .359

Again, I don’t see any issue with his bulk gaining actions.

• Jake Marisnick, who is possibly the Marlins top prospect, is just a couple weeks from being 100% after off season knee surgery.

Possible Players on the DL to Start the 2014 Season

(*) 15 Day Disabled List
(**) 60 Day Disabled List
(***) 7 Day Concussion List
(****) Free Agent
Red colored entries are updates since last report.

Major League Report

Minor League Report