Ever since last July, when the Phillies first contacted the Red Sox about a potential Clay Buchholz trade, the veteran righthander was a person of interest. The rebuilding Phillies saw him then as a low-risk addition, someone who could benefit from fleeing the cauldron of negativity that formed around him in Boston.

There was no match. Then Buchholz finished strong, the Red Sox acquired ace Chris Sale, and the Phillies maintained talks about a deal that was consummated Tuesday.

"This wasn't necessarily a position that we were targeting to fill," Phillies general manager Matt Klentak said, "but we felt that the opportunity was right."

So the Phillies were happy to spend $13.5 million and a minor-league player, Josh Tobias, to bolster a crowded starting rotation. It was a trade that fit everything the Phillies have attempted to do this winter: Improve the 2017 roster without blocking young players and resisting the shackles of a long-term financial commitment.

The Phillies did that earlier this offseason with the acquisitions of Howie Kendrick, Joaquin Benoit, and Pat Neshek. But the presence of Buchholz is a little different in that it will directly affect a younger arm; one will be pushed out of the rotation. Assume Buchholz, Jeremy Hellickson, Jerad Eickhoff, and Vince Velasquez are in the rotation. That leaves Aaron Nola, Zach Eflin, Jake Thompson, Ben Lively, Nick Pivetta, Mark Appel, Alec Asher, Adam Morgan and others to compete for the fifth spot.

Klentak said that did not bother him because three-fifths of the rotation will be filled by young pitchers. Some will be injured. Others will become relievers. A few will not succeed in the majors.

"If everybody in the organization is healthy and pitching well, then it's possible that, yes, it may block somebody's growth," Klentak said. "Realistically, going into spring training, we value the depth."

Klentak said the murky health of both Nola and Eflin, who are expected to have no restraints in spring training, did not factor into the decision to add Buchholz. Nonetheless, it will be fascinating to see how the organization finds innings in both the majors and triple A for all those pitchers.

Buchholz, 32, was a source of consternation in Boston. Paid like a front-line starter, he floated last season between the rotation and bullpen with mixed results. His contractual status fits the Phillies' parameters for additions this winter. If Buchholz returns to form, the Phillies could trade him again in July to a contender.

One scout who saw Buchholz at the end of the season said the pitcher showed progress because he altered his mechanics to include a higher arm slot and less of a windup. Buchholz had a 3.14 ERA with 21 strikeouts and 10 walks in 28 2/3 innings upon his return to Boston's rotation last September.

But his whole season was a disappointment. Buchholz had a 4.78 ERA in 37 games, with 21 of them starts. He has a career 3.96 ERA. His best season was in 2010, a 2.33 ERA in 28 starts. He has twice been an all-star but has pitched more than 180 innings just once in his 10-year career.

Tobias, 24, was a 10th-round pick in 2015 and reached single-A Clearwater by the end of 2016. He is a career .301 hitter with an .801 OPS in the minors, but there are doubts about whether he can stick at second base. The Phillies tried him some in left field last season. He was not considered one of the team's best prospects.

The Phillies now have 15 starting pitchers on the 40-man roster, which could lead to some becoming relievers or yet another trade. Earlier this month, Klentak said teams had called him with interest in some of the Phillies' young pitchers. Rival teams, Klentak said, are aware of his abundance of starting pitching. Whether that leads to a trade of an arm for a bat remains to be seen.

"Right now we're happy with the starting pitching depth that we've gathered," Klentak said, "and we would anticipate heading into camp with all of it."

Extra bases

To clear space on the 40-man roster for Buchholz, the Phillies designated Richie Shaffer for assignment. Shaffer, a potential bench bat, was a waiver claim last week. … Veteran catcher Bryan Holaday, 29, signed a minor-league deal with the Phillies and will come to spring training with a chance to be the backup catcher. … Former Phillies pitcher David Buchanan is headed to Japan. He signed a one-year, $750,000 deal with the Yakult Swallows.