BOSTON -- Maybe it's simply the effect of four losses in five games, all at home. Or perhaps it has to do with a looming 11-game road trip entirely on the West Coast. Whatever the reason, the Boston Red Sox's promising season suddenly feels a bit like a house of cards.

And it's time for Dave Dombrowski to really go all-in.

Dombrowski was roundly praised two weeks ago for acting swiftly and aggressively to plug leaks on the roster. The Red Sox's president of baseball operations made four trades in eight days, acquiring help for the bench (Aaron Hill and Michael Martinez), bullpen (Brad Ziegler) and starting rotation (Drew Pomeranz), and the team responded with six wins in seven games before the All-Star Game and five out of six upon its return.

But if Dombrowski really believes what he said earlier this week, that the Red Sox are "not looking to necessarily do something significant [before Monday's trade deadline] because we've already added," the past five days are proof that they still don't have enough pitching in either the rotation or the bullpen to be considered a rock-solid playoff team.

For four months, knuckleballer Steven Wright has been the Red Sox's most consistent starting pitcher. But in Tuesday night's 9-8 loss to the Detroit Tigers, Wright gave up a career-high eight runs, four in the fifth inning after the Sox had fought back from a 4-0 deficit to take a 5-4 lead. He fumbled that one-run edge by allowing a pair of walks and three hits before being lifted with two outs in the fifth.

Wright said he "actually felt pretty good," and after back-to-back solid outings against the New York Yankees and Minnesota Twins, this stinker might have been a mere outlier in an otherwise superb season. After all, it was a sticky night at Fenway Park, and he appeared at times to struggle to grip his knuckleball, a common problem in humid conditions. But Wright also has worked 132 2/3 innings, more than ever before in the big leagues, and has given up more than three earned runs in three of his past five starts.

Fatigue might also be a factor for Pomeranz, acquired July 14 from the San Diego Padres for touted pitching prospect Anderson Espinoza. Pomeranz has logged 111 innings, his personal season high at the major league level, and after the lefty delivered six solid innings Monday night, manager John Farrell said the Red Sox will try to cap him at about 100 pitches per start through the end of the season.

Nevertheless, Farrell tried to downplay the notion that the Sox are concerned about Pomeranz and Wright expending more bullets than ever before.

"We're talking about two guys, you can look at the track record and point to a number of innings they've pitched in the past, but these are also guys who are 27 and 31 years of age," Farrell said. "We're not looking at younger pitchers at the beginning of their career. Steven is coming off a game [last week] in which he was in complete, total command for eight innings. I can't say at this point that innings are an issue for either guy."

OK, but when you combine their workloads with ace lefty David Price's four-month underperformance and the lack of reliability of Wednesday's starter Eduardo Rodriguez, it's clear to see why the Red Sox rarely win low-scoring games. Consider this: When they score fewer than five runs in a game, they're only 8-30, compared to 47-13 when they score more than five.

The big fish, quite clearly, is Chicago White Sox ace Chris Sale, who is nearing the end of a five-game team-imposed suspension for reportedly cutting up collared throwback uniforms that he found to be uncomfortable. The White Sox would rightly expect a multiplayer, prospect-loaded return for their 27-year-old perennial Cy Young Award candidate with the most club-friendly contract in the majors, and the Red Sox are as well-positioned as any team to make a compelling offer by virtue of their young group of big leaguers and fertile farm system led by elite prospects Yoan Moncada, Andrew Benintendi, Rafael Devers and Michael Kopech.

It could be a match, if either team actually has the guts to do it.

There may be no time like the present for the Red Sox, who have only this one chance to win another World Series with retiring franchise icon David Ortiz in the same high-scoring lineup as talented youngsters Xander Bogaerts, Mookie Betts, and Jackie Bradley Jr.

"We have five solid starters," Dombrowski said earlier in the week. "I think Rodriguez is throwing the ball much better, gives us a real solid chance to win. We look for Pomeranz to pitch well for us. We have five solid starters. Could they be better? Sure. Everybody, if we had five All-Star starters, we're better. But we have five guys we like."

Maybe Dombrowski really believes that. Perhaps he's merely posturing.

Regardless, until the Red Sox's five starters begin to pitch better as a group for an extended period, their chances of reaching the postseason will still seem at times like a shaky proposition.