The Red Sox continued their recent frenzy of player acquisitions by filling their last glaring need in a trade with the Padres that brought All-Star lefty starter Drew Pomeranz on board.
The deal came at no small cost. The Red Sox parted with right-hander Anderson Espinoza, their fourth-ranked prospect (and No. 1 rated pitcher) by MLBPipeline.com.
The trade comes just two days after Pomeranz fired a scoreless inning for the National League in the first All-Star appearance of his career. He is expected to make his Red Sox debut on Wednesday at Fenway Park against the Giants.

The Red Sox (49-38) trail the Orioles by two games in the American League East and open a three-game series at Yankee Stadium on Friday night.
"First and foremost, he's a good pitcher. He's grown over the last few years," said Dave Dombrowski, president of baseball operations. "He's a very good pitcher, as shown by him pitching in the All-Star Game. Has three quality pitches, really changed the mix of his pitches. He has a premium above-average breaking ball, he has a fastball that he knows how to use, he gets it up to 94, but he changes speed on it. He's added a cutter."

For weeks, Dombrowski had been trying to patch up his team's rotation, and he was able to achieve his goal.
"Well, I think, again, you can always get better. There are no perfect clubs out there," he said. "But we've really been able to address our major needs at this point. We have four guys, and we're hopeful [Eduardo Rodriguez] will step up at this point when he pitches on Saturday. And we'll see what else happens beyond that."
This is the third significant deal Dombrowski has made in the last week, and he could be done with the bulk of his non-waiver Trade Deadline work.
In a two-day span at the end of last week, the Red Sox got a veteran right-handed bat from the Brewers in Aaron Hill and a solid reliever with closing experience in Brad Ziegler in a trade with the D-backs.
"I like our club," said Dombrowski. "I liked our club before, but it was apparent we had a couple of things that needed to be addressed. We have a very good offense, and I like the combination of the veterans and the young guys."
The Red Sox have perhaps the best offense in the Major Leagues, led by the All-Star quartet of David Ortiz, Mookie Betts, Xander Bogaerts and Jackie Bradley Jr.
Pomeranz gives the rotation support behind David Price, Steven Wright and Rick Porcello. The Red Sox hold Pomeranz's contractual rights for the 2017-18 seasons.
Ziegler gives manager John Farrell a key arm in the bullpen at a time when closer Craig Kimbrel (surgery on left knee) and setup man Junichi Tazawa (impingement in right shoulder) are both on the disabled list.
The 18-year-old Espinoza was signed by the Red Sox out of Venezuela in 2014. At Class A Greenville this season, he is 5-8 with a 4.38 ERA in 17 starts.
"He's a youngster that we like a great deal, understandably," said Dombrowski. "It was a strong price to pay. We looked at him as being a few years away from the Major Leagues, by all means, but he is a young guy that we like. We are very deep, we think, with quality prospects in our organization. We were able to protect some of our other people with a one-on-one trade. He wasn't someone we wanted to give up, but we thought, under the circumstances, if we were going to acquire somebody like Drew, somebody that just pitched in an All-Star Game, that it was going to hurt in that respect.
"We think he makes us better now. It's a sacrifice for the future, but we also think we're deep enough to be able to cover that up."
The Red Sox and Padres also made a big deal last November, when Boston sent four prospects (Manuel Margot, Javier Guerra, Logan Allen and Carlos Asuaje) to San Diego in exchange for Kimbrel.
Pomeranz, 27, was the fifth overall pick in the 2010 Draft by the Cleveland Indians. This is the fourth time he has been traded. He has also pitched for the Rockies and Athletics.
After Pomeranz served as a swingman for Oakland the last two seasons, the Padres made him exclusively a starter for the first time since 2012, when he was with Colorado.
Clearly, Pomeranz rewarded the faith the Padres put in him, going 8-7 with a 2.47 ERA and allowing just 67 hits over 102 innings while walking 41 and notching 115 strikeouts.
"He found himself in the bullpen with Oakland," Dombrowski said. "He actually, if you look at his numbers the last couple of years, pitched well. This year he just took it to another level. We like his ability, we like his age, he's 27 years of age, coming into the prime years of his life."
Fantasy spin | Fred Zinkie (@FredZinkieMLB)
With a 2.47 ERA, a 1.06 WHIP and a 10.1 K/9 rate, Pomeranz was a borderline mixed league ace during the first half of the season. Owners who added the left-hander via waivers in April may be wise to follow the Padres' lead and put him on the trade market this month. In addition to losing the benefits of working at pitcher-friendly Petco Park, Pomeranz will be stepping into an American League that contains seven of the 10 highest-scoring lineups to this point in the season. Having already thrown more innings than in any previous big league campaign, the 27-year-old could wear down against deep offenses in the second half.