Injury derails Tanaka's rookie season

AP Photo/Tony Dejak

Masahiro Tanaka’s rookie season will be on hold due to a partially torn ligament in his throwing arm.

The partially torn ligament in Masahiro Tanaka’s throwing arm derails what’s been a solid rookie season for the New York Yankees ace.

Masahiro Tanaka
2014 Season

Tanaka’s season has been a successful one: 2.51 ERA, 135 strikeouts to 19 walks in 129 1/3 innings, and the Yankees have won 13 of his 18 starts.

But Tanaka hadn’t pitched well of late, going 1-3 with a 4.25 ERA. And maybe more telling, his strikeout rate dropped 10 percentage points in that span, to 19 percent after he posted a 29 percent strikeout rate across his first 14 starts.

One of the big differences? Tanaka has had less success getting batters to swing at pitches out of the strike zone.

• In his first 14 starts, Tanaka induced an average of 23 swings at pitches out of the strike zone per game. In his past four starts, he’s averaging a little more than 18. His two games with his fewest number of swings at pitches out of the zone have come in his past four starts.

• In his first 14 starts, 39 percent of Tanaka’s pitches out of the zone resulted in swings – the highest rate among starters in MLB. Since that point, he ranks a good-not-great 15th among starters.

• In his first 14 starts, batters hit .121 with two strikes, and 52 percent of his plate appearances that reached two strikes ended in a strikeout. In his past four, batters are hitting .260 with two strikes, and only 42 percent of his plate appearances that reached two strikes have ended in a strikeout.

• Perhaps because of this, he’s being forced to throw more strikes – and batters had more success against pitches in the strike zone. He threw 44 percent of his pitches in the zone in his first 14 and 48 percent since. In his first 14 starts, he allowed 23 hard-hit balls on pitches in the strike zone per 100 at-bats; in his past four, he’s averaged 33 hard-hit balls per 100 at-bats.

The injury is yet another blow to the Yankees starting rotation.

Of the pitchers on the Yankees starting rotation on Opening Day, all but Hiroki Kuroda are on the disabled list. CC Sabathia, Ivan Nova and Michael Pineda are all on the 60-day disabled list.