Last season, Boston scored 872 runs, third most in the majors. Bay drove in 119 of them. That's 14 percent of the team's entire offense. Now that the left fielder has gone to the National League, the Red Sox are left with a huge offensive hole to fill.
Mike Cameron is the new outfielder who will join Boston's starting lineup next season. His offensive numbers from last year — .250 batting average, 24 home runs, 70 RBIs — obviously don't fill that void. Even Cameron's best season ever — .267/25/110 — was not as good a season at the plate as Bay had with the Red Sox last year. And that came in 2001 with the Seattle Mariners.
To be precise, Jacoby Ellsbury will actually replace Bay in left field next season. Ellsbury will change positions so that Cameron can take over the center-field duties. It will be a very good defensive outfield, one of the best in the game. The Red Sox are hoping increased run prevention on the defensive side will help make up for decreased run production from the outfield on the offensive side.
There will be three new starters in the lineup most nights next season. Adrian Beltre replaces Mike Lowell as the team's primary third baseman, and Marco Scutaro is the new shortstop. Last season, starting duties at short went mostly to Nick Green and Alex Gonzalez.
In 2009, Lowell hit .290 with 17 home runs and 75 RBIs. Green (.236/6/35) and Gonzalez (.284/5/15) combined to start 117 games at short. Julio Lugo (.284/1/8) and Jed Lowrie (.147/2/11) started the other 45 games.
By comparison, Beltre (.265/8/44) is coming off a subpar season, while Scutaro (.282/12/60) comes to Boston on the heels of his best major league year at the plate. Will offense from the new infielders help make up for the loss of Bay in the outfield?
Probably not. Boston's hope is that better defense and the best starting rotation in baseball (thanks to the addition of free-agent John Lackey) will lead to another postseason berth.
It's a sound premise, one that is increasingly held by more and more teams. Here in Boston, however, we've spent a winter watching the Bruins play good defense yet lose plenty of games. You've still got to score more than your opponent if you hope to win, and fans are concerned that the Red Sox may not have enough offense.
The good news is that the team has shown that it will address any offensive concerns during the season. Last year, the Red Sox saw their batting average decline in each of the first four months of the season, bottoming out at a .248 team clip in July. After scoring 141 runs in May, the Sox scored 138 in June and only 121 in July.
Boston addressed its sagging offense by adding Victor Martinez at the trade deadline. Martinez hit .336 with the Red Sox over the final two months of the season, blasting eight homers and driving in 41 runs. Sparked by the newcomer, the Red Sox hit 50 homers in August, the third-best home run total of any month in the history of the team. Their 97 homers from July 30 on led all of Major League Baseball.
Point is, the Red Sox probably haven't replaced the loss of Bay's offense for the coming season. With better pitching and defense, maybe they don't have to. But, if they do, there's no reason to believe they won't replace his bat with a midseason acquisition.
Red Sox fans wanted the franchise to add Adrian Gonzalez this offseason. They didn't get their wish. But they might get their man — or someone like that — in July if the offense is sputtering at midseason for the second straight year.
NESN.com will be answering one Red Sox question every day through Feb. 23.
Wednesday, Feb. 10: How can the Red Sox cut down on stolen bases allowed?
Friday, Feb. 12: How will Adrian Beltre handle the pressure of playing in Boston?