When you extend an inning the pitcher has to throw more pitches. Most of those extra pitches will be thrown under "duress". It's much harder on a pitcher's arm to throw 30 pitches in one inning vs. throwing 30 pitches in three innings. Injuries are often tied to innings or pitch count but many who have studied pitching injuries feel pitching under "duress" is a bigger factor. Pitching one long inning with men on base is more stressful than pitching multiple clean innings.
Even if poor defense doesn't lead to an injury it does add to the pitch count of a pitcher and that will result an an earlier exit and more work put on the bullpen which is often over worked. And lets not forget the direct consequences. More runs scored against us.
In looking at Mets up the middle defense lets start with catcher. In a recent post in this blog Christopher Soto brought up the large difference in the E.R.A of Mets pitchers when Travis d'Arnaud was catching in 2016 vs. their E.R.A. when Rene Rivera was catching. I found an article in Newsday that had a little different numbers than those that Christopher had. I'm going to use Newsday's not because I think their's is better but because they're a little bit more favoriable to d'Arnaud and I want to give him the benefit of the doubt. Mets pitchers when pitching to d'Arnaud had a 4.21 E.R.A. compared to a 2.77 E.R.A. when pitching to Rivera. Just watching how Rivera handles the Mets pitching it is quite obvious he is the better defensive catcher but 1.44 runs per game! Now another point in d'Arnauds behalf is that Rivera got to catch most of Syndergaard's innings. So that may account for some of the difference but certainly not all of it. d'Arnaud's catching E.R.A. is at least .5 above the Mets pitching staff minus Syndergaard. So d'Arnaud cost the Mets at least .5 runs per game. That is 81 runs over 162 games. Can his bat ever produce enough to close the gap even if Rivera was totally dead weight as a hitter.
The Mets middle infield in 2016 was a huge improvement over that of 2015. Cabrera and Walker were sure handed but they were still below league average do to the lack of range. They're projected to be the worst middle infield in 2017 with -19 runs saved.
Granderson will be well below par in Centerfield. Will his 130 strike outs and 30 solo homeruns justify him playing Centerfield.
How I would address this. If d'Arnaud doesn't show huge improvement, and I haven't liked what I've seen so far you have to make a trade or go with Rivera. Catching is to important of a position defensively. .5 runs plus per game is to much of a gap for even Piazza to make up with his bat let alone d'Arnaud. Move Walker to 1st. Duda needs to be getting swings every day if he is going to get to a point where he is going to be productive. I don't see that happening. Move on. Move Cabrera to 3rd. He is not our best option or even our 2nd best option at short stop. Last year it was obvious Reyes was better suited for shortstop. I was fine with the Mets being loyal. This is a new year they need to be in a win now mode. Make Reyes the everyday 2nd basemen. He still shows great range as a middle infielder. Don't wait until mid summer. Now is the time for Amed Rosario to take over the short stop position. Play Conforto everyday in centerfield with Lageras as a late inning substitution. I orginally had Lageras as the everday Centerfielder but that would be giving up to much offensively.
My proposed 2017 opening day lineup
1. Reyes 2nd base
2. Cabrera 3rd base
3. Cespedes Leftfield
4. Bruce Rightfield
5. Conforto Centerfield
6. Walker 1st base
7. Rosario Short Stop
8. Rivera Catcher
I think the offense suffers a little but the defense moves from dead last to a top 10 defense.