Is Yankees' super-rookie Masahiro Tanaka finally coming down to earth?

Masahiro Tanaka looked invincible for the first three months of his major league career, but since the calendar turned to July, the league has appeared to catch

Masahiro Tanaka looked invincible for the first three months of his major league career, but since the calendar turned to July, the league has appeared to catch up to the Yankees' ace. On Tuesday night at Progressive Field, the Indians touched up the 25-year-old righty for 10 hits and five runs -- both season highs -- over 6 2/3 innings en route to a 5-3 win.

In isolation, such an outing would hardly raise an eyebrow -- even Clayton Kershawtakes his lumps once in awhile -- but this was the second outing in a row in which Tanaka set highs in hits and runs allowed. Last Thursday, he surrendered nine hits and four runs to the Twins, his first non-quality start after tying a major league record with 16 straight quality starts to begin his major league career:

Rank	pitcher	team	start	end	Gs	Ip	era
1T	Masahiro Tanaka	Yankees	4/4/14	6/28/14	16	115 2/3	2.10
	Steve Rogers	Expos	7/18/73	9/25/73	16	128 2/3	1.40
3	Brandon Webb	D-backs	4/27/03	7/8/03	13	90	2.20
4T	Al Brazle	Cardinals	7/25/43	6/16/46	12	103	1.22
	Ed Wright	Braves	8/3/45	9/29/45	12	104 1/3	1.98
6	Jesse Barnes	Braves	9/8/15	7/16/16	11	95	1.23
7T	Cy Blanton	Pirates	9/23/34	5/26/35	10	88	1.23
	Wilbur Cooper	Pirates	4/15/14	5/30/14	10	82 2/3	1.31

Dating back to his June 22 start against the Orioles, Tanaka has allowed 14 runs in 29 2/3 innings, raising his ERA from 1.99 to 2.51; he's taken the loss in three of those four turns, though low run support -- a combined one run in the first two of those starts -- is as much to blame as his own performance. More unsettling, he's been touched for eight homers over his past seven starts dating back to the beginning of June, a rate of 1.4 per nine. For as remarkable as his per-nine walk and strikeout rates (1.3 and 9.4, respectively) are, his 1.0 homers per nine is rather ordinary.

Two of those homers came on Tuesday night, and they were big ones. Through his first five innings, Tanaka scattered six hits and one walk while striking out five; the Yankees led 3-2, having scraped out a pair of first-inning runs against Cleveland starter Trevor Bauer and added another in the second. On Tanaka's first pitch of the sixth inning, Lonnie Chisenhall singled, and then four pitches later, Nick Swisherpunished a hanging slider for a two-run homer that gave Cleveland the lead. One inning later, Michael Brantley -- who had already collected a pair of RBI doubles off Tanaka in his first two trips to the plate -- smashed a 92 mph fastball left over the middle of the plate for a solo homer that capped the scoring at 5-3.

It's fair to wonder if Tanaka's struggles owe something to fatigue. After throwing 116 pitches in his complete-game loss to the Red Sox on June 28, his second-highest total this season, he threw a season-low 85 against the Twins and then 99 on Tuesday night, his first back-to-back starts below 100 pitches. Even so, his 14 swings and misses were on target for a pitcher who came into the night with an MLB-high 13.7 percent swinging strike rate. Via BrooksBaseball.net's PITCHf/x data, his average velocity -- 92.0 mph on his four-seamer, 87.4 on his splitter -- wasn't out of line with his season to date, even if the results were.

Perhaps most notably, this was the first time since coming stateside that Tanaka had started back-to-back games on four days' rest, something he'll have to do once more in his final turn before the All-Star break. He's pitched better on five days' rest, the amount of time he regularly had in Japan, though within the small samples of this half-season, the advantage has been slight:

Rest	Gs	ip	hr/9	bb/9	so/9	so/bb	fip	era
4 days	8	55 2/3	1.0	1.6	8.6	5.3	3.34	3.07
5 days	8	58 2/3	1.2	1.2	9.8	8.0	3.25	2.30

I've excluded Tanaka's two starts on six days' rest, during which he's put up a 1.20 ERA over 15 innings. There's not a whole lot to separate the remaining two groups of starts, particularly according to Fielding Independent Pitching, an estimate of his ERA based upon his peripherals.

For his part, in his postgame comments, Tanaka didn't feel as though his lack of rest was a problem. His command was another story. Via Chad Jennings of The LoHud Yankees Blog:

“I didn’t feel that bad going out on the mound tonight,” he said. “Actually, I did feel that my fastball was a bit better than last time. … I think it had a lot to do with my command, the command of my pitches. I feel that a lot of my pitches were going right down the middle where it’s actually pretty easy for the batters to hit. I think that would be one of the big reasons.”

In the end, Tanaka’s night boiled down to a rather typical performance undone by a couple of atypical mistakes. Like Kershaw, he’s raised the bar so high that any deviation from excellence runs the risk of being over-analyzed. Still, he may be running on fumes as the break approaches, and the Yankees will need him to resume his previous dominance if they’re to have a shot at a playoff spot.

UPDATE: Bad news for Tanaka and the Yankees, as the New York Post reports that the right-hander will undergo an MRI on his arm. No further details were provided as to why the MRI was deemed necessary, though an injury would help explain Tanaka's recent struggles. Additionally, at his postgame press conference Tuesday, Tanaka said, "I do understand the reason why I was struggling today, but it's really difficult for me to tell you why that was," another sign that he may have been experiencing some physical discomfort.