The clock is counting down to Sunday’s 4 p.m. non-waiver trade deadline. What the Red Sox do by the end of the week could be the key to what they are able to accomplish in October.

What they don’t do could be equally important.

The Sox near the deadline in a position of great strength. They opened their series with the Kansas City Royals Monday night with a three-game lead in the AL East. Prior to this homestand, it had been more than two years since they led the division by that big a margin.

More important, the Sox held an 8 1/2 game lead in the overall playoff race.

With 100 games behind them, the Red Sox are pulling away from the pack with the best offense in baseball.

Is that offense good enough to go the distance? That’s what GM Theo Epstein will have to decide by Sunday.

With a shoulder injury compounding J.D. Drew’s season-long offensive struggles, there is now a clear need for help in right field.

Josh Reddick, the rookie who has surprised everyone with his numbers in the past month, has alleviated the problem in right.

But he’s another lefty bat, joining Jacoby Ellsbury and Carl Crawford as left-handed outfielders. Adding a right-handed bat to the outfield seems an obvious move, even with the play of Reddick.

Is additional offense what the Red Sox really need? After scoring 22 runs in three games against the Mariners this weekend, the Sox began the week with 541 runs scored — by far the most in baseball.

They’ve got the best batting average as well as the highest on-base percentage and slugging percentage in the game.

The bigger concern right now could be pitching. The Sox entered Monday night’s game with a 3.93 ERA, 16th best in baseball. Their starting rotation’s ERA (4.10) ranks 21st.

Jon Lester’s return from the disabled list Monday night will certainly help those numbers.

But there are still concerns about Clay Buchholz, although he threw off a bullpen mound Monday and said his back was improving.

John Lackey has pitched better lately, but he still has been a mystery to everyone this season.

Are you confident with Lackey taking the mound in an ALCS game this October? He was a big-game pitcher with the Angels, but he’s got a long way to go to regain that form — and the team’s confidence.

The Sox have managed to patch together a rotation that has gotten them this far.

Andrew Miller is still very much an unfinished project. Kyle Weiland is back in Triple-A where he belongs.

And while the Sox are 9-4 in games started by Tim Wakefield, he has posted a 7.06 ERA in his last five starts.

An additional arm could, at worst, find a home as Boston’s fifth starter down the stretch. Depending on the health of Buchholz and the gains made by Lackey, he may have to be much more.

The Red Sox will be in Chicago when the trade deadline strikes and the White Sox have been reportedly shopping Edwin Jackson.

Jackson’s ERA (3.92) would be the fourth best among Boston’s starters.

At the end of the day, the Sox may do very little.

They’ve got the best record in the American League and a huge playoff cushion.

The return of Lester, and the eventual return of Buchholz might be the best mid-season additions of any team in baseball.

But we’ve seen Epstein make bold moves in the past.

He shocked baseball with July 31 deals involving Nomar Garciaparra, Manny Ramirez and Eric Gagne.

He has also had years where smaller moves have paid off.

Last season he acquired Jarrod Saltalamacchia, who had four RBI Sunday and is hitting .279 this month.

He has become the Red Sox primary catcher and is only 26 years old.

Coming into the season, many thought catcher would be a question mark for the Sox. With the play of Saltalamacchia, it isn’t.

We’ll see what other questions are answered by the end of the week.

Tom Caron is the studio host for Red Sox broadcasts on the New England Sports Network. His column appears in the Press Herald on Tuesdays.