NEW YORK -- How concerned is Red Sox president of baseball operations Dave Dombrowski about his team's disappointing start?

"I'm concerned because we haven't played well, but I'm not overly concerned," Dombrowski said. "It's early in the season and I've been through this where you go through streaks with clubs. Really, when you start looking at our club, you say, 'Well, what facet of your club is playing really well?' And we're really not playing very well anywhere.

"Our starting pitching hasn't been very good, our defense hasn't been overly good, our hitting hasn't been like it's been capable of being. So we've just had a tough start really is what it comes down to. I've seen these things happen before."

Dombrowski did make a change to the catching situation on Tuesday when Blake Swihart was designated for assignment and Sandy Leon was called up from Triple-A Pawtucket.

• Sox recall Leon from Triple-A; Swihart DFA'd

But don't expect the longtime executive to overreact with a bunch of early-season moves.

"When you have a club that's struggling in a lot of different areas, which we are, you try to fix little things at a time," Dombrowski said. "For us, OK, we've tried to get a little better defensively behind the plate and a little comfort zone with the starting staff working with him.

"I think our starting pitching has started to show some improvement, with [Eduardo] Rodriguez and [David] Price and the games they threw. We're hoping that continues. And I think our offense will get going. They're a good offense. They just haven't done it so far."

Cora: No World Series hangover

Red Sox manager Alex Cora remains adamant that his team's shaky start has nothing to do with a "World Series hangover."

"Nah, I don't believe in it," Cora said. "Right now, we're not playing good baseball. There's no excuses. We went to the West Coast, went to Seattle, we lost three out of four; we went to Oakland, lost three out of four; went to Arizona, I think we played better for two out of three days.

"We haven't been consistent with the things that we do. But I said it before the season: We believe in what we believe. We believe in our principles, baseball-wise. We haven't done it -- attention to detail, baserunning, defense, pitching. You name it. We haven't been consistent at it. We just have to let the season play out, too. It's 162 games."

Red Sox defend Pedroia plan

After serving as the designated hitter on Sunday and Monday, second baseman Dustin Pedroia didn't start on Tuesday.

Pedroia needs maintenance days off for his surgically repaired left knee, much of it mandated by the training staff. The Red Sox aren't second-guessing their decision to put him on the roster after just a three-game Minor League rehab assignment.

"He felt he was ready to go," said Dombrowski. "To stretch this [rehab assignment] out over a lengthy period, it would take a long time period to get through the whole time. He's not going to be ready to play every day for a lengthy period. So we're willing to deal with the situation."

The veteran is 2-for-19 at the plate, but Pedroia has made some strong plays on defense.

"He's coming back in a tough situation. He's not there from an offensive perspective, but guys don't miss two years and come back and swing the bat like they're an All-Star," Dombrowski said. "So he's going to take some time to find his timing. He's working on it. He's hit some balls decently. He played second base great the other day turning the double plays."

Cora said that Pedroia is expected to start at second base on Wednesday night.

"It's still a situation where only time will tell, because the real key for Dustin is going to be when he plays [several] days in a row," Dombrowski said. "We're not at that point yet. As time goes on, it's apparent he can handle short term. We're very happy and the doctors are very happy and he's very happy with it."

Worth noting

• Though left fielder Andrew Benintendi was out of the lineup for the second straight day after suffering a right foot contusion Sunday, Cora said Benintendi is much-improved and could start Wednesday night.

• The Red Sox added righty Erasmo Ramírez from Triple-A Pawtucket prior to Tuesday's game. He replaces righty Marcus Walden, who was optioned to Pawtucket after Monday's game. A non-roster invitee to Spring Training, the 28-year-old Ramirez is 1-0 with a 1.13 ERA over two starts for Pawtucket. Ramirez will be used as bullpen depth in Boston.

• Infielder/outfielder Brock Holt (scratched cornea, right eye) started a Minor League rehab assignment for Triple-A Pawtucket on Tuesday. Holt could be ready to rejoin the Red Sox by this weekend's three-game series at Tropicana Field against the Rays.