OAKLAND -- This is what makes a team believe that things are beginning to turn, when it wins a series because its starting pitchers had enough resilience, resourcefulness and yes, a little luck, to succeed even without their best stuff.

It happened Monday night with Rick Porcello, who gave up nine hits, a walk and a wild pitch in five innings to the Oakland Athletics but kept the Boston Red Sox in a game they ultimately won 5-4. It happened again Wednesday afternoon with left-hander Wade Miley, who found himself unable to command his fastball but nibbled his way out of one jam after another with his slider, curveball and changeup in a 2-0 win over Sonny Gray and the A's.

It didn't happen Tuesday night for Justin Masterson, who lasted just seven outs and almost certainly is headed for the disabled list after being scratched from his next start Sunday in Seattle.

Now the onus is on right-hander Joe Kelly, whose struggles over his last four starts (21 earned runs in 21 1/3 innings, 8.86 ERA, at least five runs allowed in each start) rank as perhaps the most perplexing aspect of Boston's slow start this season. Club officials privately admit to being baffled by Kelly, who is smart, young (25), and blessed with an arm capable of throwing 97 mph darts. Outside of a shutdown performance in the Bronx (one-hitting the Yankees over seven innings April 11) Kelly has hardly resembled a pitcher worth sacrificing John Lackey for.

The comparison has looked even worse because of how well Lackey is pitching for the Cardinals, and because the other player acquired by Boston from St. Louis in that trade, outfielder Allen Craig, was demoted to the minors Sunday.

After Kelly was shelled in Toronto on Saturday -- walking seven, giving up a three-run home run, throwing a wild pitch and being charged with two errors (one for obstruction) all in the first four innings -- the Sox called up knuckleballer Steven Wright and the thought was that Kelly's spot in the rotation was in jeopardy. Now Wright will probably be slotted for Masterson, and Red Sox manager John Farrell said he wanted to give new pitching coach Carl Willis a chance to evaluate the staff he has inherited.

So what has Kelly focused on since his last outing?

"Not focusing," he said, not ironically. "Probably the best way to do it. Just relax. The stuff is there. Just got to pitch better. No panic mode for me. I'll let other people do that for me."

Ask him if he will be pitching for his spot in the rotation Friday, he said, "I don't feel that way, no. I just don't think about it right now." But he did concede there are times he places undue pressure on himself.

Kelly said mechanically he is where he needs to be. Physically, "I'm not hurting at all. Nothing."

He pleads guilty as charged to Farrell's assertion that he at times has thrown the same pitch too many times in a row.

"It's still about Joe Kelly understanding what makes him so efficient, and that's what we continue to stress and talk about and outline in game plans," Farrell said. "Ultimately, it's in those moments of making a pitch selection based on what led up to that, whether it's too many consecutive fastballs, too many consecutive breaking balls.

"There's nothing mechanical. He's a good athlete who repeats his delivery, but he yanked a number of pitches to his glove side the other day in Toronto."

After last July's trade, Kelly took a regular turn in the Sox rotation, and while he walked too many batters (32 in 61 1/3 innings), he held opponents to a .215 average and pitched to a 4.11 ERA. He threw well enough to be viewed with the highest ceiling of all the Sox starters in camp this spring. But the command issues have continued. Opposing batters might be hitting just .237 against him -- lowest average among all Sox starters -- but the mistakes have come at key times, and with runners on base, many of his own creation.

"I'm still working on pitching, and learning," he said. "It's something I've got to figure out on my own."