Suddenly, the Sox appear to be in a mound of trouble. There’s been a lot of bitching about the pitching this week, and with good reason. The starting rotation – heralded as the best in baseball during the offseason – is taking on water. Two-fifths of the rotation is a mess, and the team’s ace is inconsistent at best.

It is pitching that made this team co-leader of the division on Memorial Day, and it is pitching that saw the team suddenly fall off the pace of the surging Yankees. (Can they please stop playing the Orioles?)

The dreaded June Swoon started early for the Sox, which got a head start in late May. In one week, the team lost four games on New York, in large part because of starting pitchers that couldn’t go deep into games, let alone win them.

It all started with Derek Lowe’s disastrous run, that began with the infamous 10-day layoff in April. He hasn’t pitched well since his first start. No one knows if, or when, Lowe can recover, but there’s no better time than now. He took his 4-5 record and 6.84 earned run average to the mound in KC Sunday, having won one game in the past five weeks. Last year, Lowe went 5-0 in June. Let’s hope there’s something special about this month for him.

Fifth starter Bronson Arroyo has given up 11 earned runs in his last two starts – unable to make it out of the sixth inning either time. Red Sox Nation demanded that Arroyo become the fifth starter, and he’s lost three in a row. Byung-Hyun Kim is in South Korea, and manager Terry Francona admitted this week he “forgot” to ask if Kim would be returning. Don’t count on ole’ B.K. starting a game for Boston anytime soon.

When this season started, Theo Epstein envisioned Kim as a quality starter, and young Arroyo being a key long reliever out of the bullpen. Kim’s implosion forced Arroyo out of the pen, and there hasn’t been an arm good enough to take his spot in the key long-relief role. That’s why Arroyo was left in (after more than 100 pitches) to face Vladimir Guerrero in the sixth inning Tuesday night and why Francona was so slow to pull a bleeding Lowe out of Monday’s game with Baltimore.

We might actually shrug all of this off if Pedro Martinez was pitching well. He’s not. He blew a 7-4 lead on Wednesday, giving up seven runs without recording an out in the sixth. He has developed a penchant for giving up the long ball. All this after he complained about a lack of respect shown by the Sox in not giving him a new contract.

Francona, of course, isn’t fazed by any of this. At least not publicly. At least not yet. He’s an optimist, and believes things will work out in the end. It’s the oldest mantra in baseball: “it’s a marathon, not a sprint.” Fine, but when the cramping starts long before Heartbreak Hill, the most hardened runner knows there’s reason to worry.

There will be pitchers available between now and the July 31 trading deadline. We knew the Yankees would be in the market for a starter. We didn’t think the Sox would. Epstein doesn’t want to trade away any of his key prospects, and thought he had the goods to contend this season. If this leaking rotation continues, he may have to package some top minor-league talent for a starter that can help shore things up (and send Arroyo back to his much-needed role in the pen.)

There are more than 100 games remaining in the season, plenty of time to turn things back around. But someone needs to start these games, and the Red Sox can’t afford to wait for their pitchers to find their stuff while the Yankees pull further and further away.

Nomar will be back soon, possibly Tuesday. The offense will improve, and continue to improve as the weeks roll on. That’s good news. If the Sox can’t start getting quality starts, it will be wasted news.