With just over one third of the 2013 season already complete, the Boston Red Sox have been a pleasant surprise to fans in New England.

At 33-22, Boston sits atop the American League East thanks to a roaring offense and a stellar top of the rotation. The Sox are fifth in the league in runs per game, fourth in team wOBA and second in walk rate. Meanwhile, Clay Buchholz is the leading candidate for the AL Cy Young Award through the season’s first two months, and Jon Lester, Ryan Dempster and John Lackey have been formidable right behind him.

The Sox have played great ball over their first 55 games, as their +43 run differential indicates. But two months a season does not make, and often times it is those middle-of-the-season months that separate the contenders from the rest of the pack.

In order for Boston to keep up its winning ways, it will need continue to reach far and beyond its preseason expectations. Going forward, here are a few things to look out for in the month of June and leading into the All-Star break.

The Stretch From Hell

Starting tonight, and leading into the first three weeks of June, the Red Sox play 25 games in 27 days. 22 of those games come against teams that currently have winning records; the other three come against the surging Los Angeles Angels, who have won 10 of their last 12 ballgames and were a preseason World Series favorite.

The schedule kicks off with a crucial weekend series in the Bronx against the Yanks with first place in the division on the line. After an off day Monday, the Sox host Texas and L.A. at home before heading to Tampa and Baltimore for seven straight games with their division foes. A home double-header with the Rays and a weekend trip to Detroit – possibly the best team in baseball – highlights the tail end of the stretch, which culminates in a two-game set at Fenway with the surprising Colorado Rockies.

Oh, and if that doesn’t seem brutal enough, Boston heads into the All-Star break with a killer 10-day, West Coast road trip in L.A., Seattle and Oakland (they went 3-13 there last year), which could potentially decide the team’s fate at the trade deadline.

If the Red Sox can play .500 baseball over their next 42 games leading into the break, they’ll be 54-43 when the second half starts, on pace for 90 wins. That puts Boston in pretty good position to make a run at a wild-card berth, and maybe even the division title, as tight as the AL East has been playing.

The next month-and-a-half will be all about treading water for manager John Farrell’s club. If they do that, they’ll be in good shape.

A Buchholz Regression?

His collarbone injury aside, it’s tough to imagine Clay Buchholz keeping up the pace he’s set for himself over his first 10 starts.

The 28-year-old right-hander is 7-0 and leads the AL with a 1.73 ERA. He’s given up just two homers, and has gone at least seven innings in all but one start, a game in which he still struck out nine Twins over six innings in a 6-5 Red Sox win.

And despite evidence that Buchholz had transformed into more of a “pitch-to-contact” pitcher, he’s struck out a shade over nine batters per nine innings so far this year, by far his career best.

Of course, Buchholz’s peripherals aren’t quite as kind to him. He’s stranding 84.7% of his baserunners, good for seventh in the AL. His xFIP is 3.23 – still very good, but a skyrocketing figure compared to his miniscule ERA – mostly attributed to his “luck” with baserunners and fly balls.

The thing to take away here is two-fold. First off, if Buchholz does indeed regress to what his ERA normalizers say, he’ll still be an ace who has somehow become one of the best strikeout arms in the game. That’s the good news. The bad news is that the Sox have been relying heavily on Buchholz so far this year – and he’s come to the table in a bigger way than anyone could have possibly expected. Would Boston be in first place if Buchholz had an ERA in the low 3s instead of hovering around 2000 Pedro Martinez territory? It’s tough to say.

The best thing Sox fans can realistically hope for out of Buchholz going forward (again, his collarbone injury aside) is that he regresses a bit but still continues to come up with big strikeouts in key spots, preferably with runners on base. A successful Buchholz will really help Boston get through its upcoming stretch before the All-Star break.

Ellsbury’s Status

The Red Sox were one of the most active teams in free agency over the past offseason, but they essentially stood pat on Jacoby Ellsbury, the 29-year-old center fielder and leadoff hitter who hits free agency after the season.

Two months ago, Ellsbury’s future seemed pretty clear. He would play out the season in Boston and either leave in free agency (if the team was in the pennant race throughout the year) or be traded to a contender at the deadline (if Boston repeated its 2012 woes). All of this was predicated on the notion that Jackie Bradley Jr., who hit the cover off the ball in spring training, was the obvious 2014 Opening Day center fielder.

Bradley may still have the job on lock in the minds of the Sox’ front office, but an .121/.275/.152 through 40 plate appearances so far this year hasn’t helped his case. If anything, it might make Boston re-think its plans for next year and beyond.

Ellsbury, meanwhile, is hitting .268/.337/.372 with 21 steals, and has been playing Gold Glove defense in center. He’s not having the ridiculous year he had in 2011, when he smashed 31 homers en route to a 9.1 fWAR campaign, but he is playing like a three-win player through the first two months. That should theoretically net Ellsbury a $15 million-per-year deal on the open market this winter, but Boston could probably lock him up at a discount if they work out a deal in the coming months.

At this point, it’s difficult to imagine Boston being sellers at the July 31 trade deadline, unless an epic collapse happens over the next two months. The Sox are more likely going to be buyers, and if they really want to push for a monster mid-season acquisition like Cliff Lee, they might even dangle a prospect like Bradley (OK, that probably won’t happen, but it’s possible).

Don’t be surprised one way or another by what happens to Ellsbury. Odds are, the situation will correctly dictate how things end up.