Green or Lowrie? There's no debate

One of the oldest baseball adages goes something like this: No matter how you start the season, if you're a .300 hitter, by the end of the season, you're going to hit .300. No matter how you start the season, if you're a .250 hitter, by the end of the season, you're going to hit .250. That's just the way it goes.

Nick Green came into this season as a .240 hitter with a .656 OPS in 799 major-league plate appearances. He's a .240 hitter. Maybe he's a .250 hitter. But that's it.

He hit .275 in April and hit .321 in May. His batting average, at that point, was .298. His OPS -- on-base plus slugging -- was .783.

But, as we might have expected, he's regressing to the mean. He's 20 for 106 (.189) since June 1, and his OPS has slowly dwindled:

May: .784
June: .698
July (so far): .580

He has six hits in his last 45 at-bats (.133) with a .264 on-base percentage -- and his on-base percentage is only that high because he faced Bruce Chen and Robinson Tejeda on Sunday. (When a pitcher goes 0 for his first 13 in trying to throw strikes to Jason Bay, you have to take Green's three walks, a career high, with a grain of salt.)

Green's overall numbers, thanks to his hot start, still don't look terrible: He's hitting over .250 and OPS'ing over .700. That's led many to believe there's a debate afoot: Who's going to play shortstop full-time upon Jed Lowrie's return?

Green remains a valuable asset as an infielder. He can play at least three positions and has seen his defense at shortstop improve by leaps and bounds since a rough start to the season. (His UZR/150 was minus-16.6 in early June but is now plus-12.2, and he's gone more than a month without making an error.)

But Lowrie can hold his own defensively. A year ago, in fact, he had an UZR/150 of plus-24.6 and made zero errors in 49 games at shortstop. He's also a better hitter when he's healthy -- even with the wrist injury that plagued him last year, he put up better numbers (.739 OPS) than Green has this season (.721 OPS).

Green will allow the Red Sox to work Lowrie back slowly, but there's no question who should be starting the majority of games at shortstop at Fenway Park.