10 Questions -- No. 4: Who's on the bench?

Part 4 of a 10-day series on Red Sox questions that will be answered during spring training.

BOSTON -- As a two-for-one promotion, this is one the Red Sox prefer they hadn’t given their fans last season: Go to a Sox game, see the PawSox, too.

Twenty-one of Pawtucket’s players appeared in the big leagues for the Red Sox last season, as that I-95 shuttle between McCoy Stadium and Fenway Park was as popular last summer as the Provincetown Ferry.

Fifteen rookies played for the Sox last season, second behind Detroit (16) among AL teams. On Sept. 13 in Seattle, the Sox had an all-rookie starting outfield -- Daniel Nava, Ryan Kalish and Josh Reddick -- their first since 1987 (Mike Greenwell, Ellis Burks, Todd Benzinger). A week earlier, the Sox started three players under the age of 23 -- Lars Anderson, Kalish, and Yamaico Navarro -- for the first time since 1980 (Glenn Hoffman, Reid Nichols and Chico Walker).

Manager Terry Francona wrote the names of 25 different players as starters in the No. 9 hole on his lineup card. That includes pitchers in interleague games, so we’ll cite the 8-spot, too: 14 different players.

All of which serves as introduction to a discussion of the Sox bench entering this season, as part of our 10-part countdown to spring training, as well as the importance of organizational depth. in a season in which injuries ravage a team’s 25-man roster.

A year ago at this time, Darnell McDonald was just another journeyman minor leaguer with an invitation to big-league camp. Even after his spectacular Sox debut last April, in which he hit a game-tying pinch-hit home run and then delivered a walk-off single an inning later to beat the Rangers, the Sox were prepared to cut ties with McDonald, informing him during a May trip to play Tampa Bay that he was being designated for assignment.

Instead, the Sox discovered Jacoby Ellsbury had not recovered from his fractured ribs, they held on to McDonald, and he wound up playing in a career-high 117 games. He was the only player to appear in at least 30 games (with 10 or more starts) at all three outfield positions, and led the AL with a .429 average as a pinch hitter (6 for 14).

After a dozen years in the minors, McDonald may hardly feel he has job security, but this spring he comes to camp as the favorite to be retained as the team’s fifth outfielder. And it’s possible he could take on added importance if another team shows interest in Mike Cameron, who is being paid like a starter ($7.25 million) and may have value elsewhere as one, even at age age 38, especially if he proves he’s fully recovered from a torn abdominal muscle.

Cameron and McDonald both can play all three outfield positions -- Cameron as a three-time Gold Glove Award winner and McDonald with average skills and a throwing arm that accounted for a team-leading nine assists last season -- and also can serve as right-handed bats off the bench. Cameron hit .357 (15 for 42) with 3 home runs against lefties, while McDonald hit .294 (45 for 153) with 4 home runs. Their presence virtually assures a return to the minor leagues for more seasoning for Ryan Kalish and Josh Reddick, who potentially will be competing in 2012 for the right-field spot likely to be vacated by J.D. Drew, whose contract expires after this season. It also leaves no room here for Daniel Nava, who hit a storybook home run -- a grand slam on the first big-league pitch he saw -- then did not hit another homer in 160 more big-league at-bats.

With Jason Varitek re-signed for a 14th season to split time at catcher with Jarrod Saltalamacchia, that leaves prospects like Mark Wagner, Luis Exposito and Ryan Lavarnway in a holding pattern in their trek to the big leagues. Wagner missed considerable time last season with a fractured bone in his left hand and subsequent wrist problems.

The other player expected to start the season on the bench could have the biggest role of all: Jed Lowrie, who after losing nearly two full seasons to wrist woes and the first half of last season to mononucleosis displayed all the skills that had him once pegged as the Sox shortstop of the future.

Francona attempted to cut off any brewing controversy by declaring Marco Scutaro will start at short this season. With defensive whiz Jose Iglesias no more than a year away, Lowrie’s greatest value to the club may well be in the role they envision for him: as a super-utility guy who can play all four infield positions. He posted a .907 OPS last season, hitting a career-best 9 home runs in just 171 at-bats. Being a switch-hitter only heightens his appeal in that role, and with Scutaro needing to show he’s over a pinched nerve in his neck and strained rotator cuff in his shoulder, and Dustin Pedroia coming off a fractured left foot, Lowrie could receive plenty of playing time.