BOSTON -- Although he earned points for creativity by designing those snazzy "He's The Ace" T-shirts, Clay Buchholz proved once and for all last season that no, he isn't capable of leading a starting rotation.

A year later, he's demonstrating he isn't much of a No. 2 starter, either.

All Buchholz needed to do on Thursday night to extend the Boston Red Sox's winning streak to a season-high five games entering their first series of the season against the archrival New York Yankees was defeat the sad-sack Atlanta Braves, a team that had lost eight consecutive games, hit exactly one home run since April 10 and scored no more than four runs in a game since April 19.

No sweat, right? Any old No. 2 starter should be able to handle that.

Not Buchholz.

For the fourth time in five starts this season, Buchholz gave up five runs in an eventual 5-2 loss to the Braves. For the fifth consecutive start, he failed to complete the seventh inning. He fumbled a 1-0 lead in the second, and when the Red Sox cut the deficit to 3-2 in the third inning, he gave up another run in the fourth on a two-out RBI single by Braves leadoff man Nick Markakis.

At least Markakis is an accomplished hitter, an AL East rival for years with the Baltimore Orioles. The worst part of all this for Buchholz is that he issued four walks, three by .200-hitting Braves second baseman Jace Peterson, and gave up two hits to No. 9-hitting Mallex Smith, a 22-year-old rookie with one hit and six strikeouts in his previous 16 plate appearances.

While Buchholz offered a relatively kind self-assessment -- "Didn't feel sharp; fastball command wasn't there," he said -- manager John Farrell was more pointed in his evaluation of the veteran right-hander.

"No disrespect to Peterson, you're wanting to force contact. He hasn't hit for a high average," Farrell said. "You're ideally liking a guy to go and attack the strike zone, work ahead in the count, and that was not the case.

"Tonight was not sharp."

When spring training began, Farrell slotted Buchholz into the second spot in the rotation behind ace David Price. But through five starts, Buchholz has a 6.51 ERA, his highest monthly mark since May 2014, when he notched a 7.40 ERA that was so ugly, he wound up on the disabled list to deal with a minor knee injury and to clear his muddled head.

To be fair, Buchholz didn't pitch poorly on Saturday in Houston -- at least until he left a fastball over the plate that Astros slugger Colby Rasmus belted for a grand slam. And he appeared to be turning a corner with 6⅔ scoreless innings against the Toronto Blue Jays on April 18 at Fenway Park.

Losing to the Braves, then, represents another step back for Buchholz, whose problems are a matter of poorly located pitches, according to Farrell, rather than the quality of his stuff.

Over the years, it has been injuries more than ineffectiveness that has kept Buchholz from being classified as a legitimate top-of-the-rotation starter. So he didn't have any answers on Thursday night for what adjustments he must make in order to put together a string of quality starts.

"Not give up five runs? I don't know," he said. "I felt good with most of my pitches for the most part. Like I said, fastball command wasn't there. You can't just walk guys, because that usually ends up hurting you, and they hit some good off-speed pitches. They hit some good fastballs that I felt like weren't that bad of pitches and they weren't [hit] at anybody."

Buchholz has had some bad luck, as evidenced by opponents' .314 batting average on balls in play. But mostly, he has just been bad at a time when the Red Sox have gotten a collective 4.80 ERA from their starting rotation, with young lefty Eduardo Rodriguez and right-hander Joe Kelly on the disabled list.

With Rodriguez still at least one minor league start away from returning from a spring training knee injury and Kelly (shoulder impingement) not yet throwing from a mound, they certainly need their purported No. 2 starter to be better.

"I wouldn't ever go on a bad streak if I knew what I had to do to not go on them," Buchholz said. "I think it just happens sometimes. Team is going good and everybody is throwing the ball well, and it's falling on me right now. I haven't been throwing the ball as well as the other guys. It usually stops and turns and goes the other way at some point too. Just got to keep grinding and stay with it."

Otherwise, the Red Sox will be hard-pressed to find a reason to stay with Buchholz.