Offense is at a premium in baseball. That is why the Phillies could not acquire Joey Gallo or Nomar Mazara from the Texas Rangers in last week's Cole Hamels blockbuster, and why they were never going to get Mookie Betts or Blake Swihart from the Boston Red Sox, Corey Seager from the Los Angeles Dodgers, or Kyle Schwarber from the Chicago Cubs.

It's far from a coincidence that 10 of the 12 minor-leaguers the Phillies acquired in their six trades since December are pitchers. In the sport's current landscape, teams are reluctant to part with premium position-player prospects, especially those boasting rarely seen power such as the 21-year-old Gallo.

The Phillies now feature a power-hitting prospect of their own in Jorge Alfaro, Gallo's former double-A teammate. The 22-year-old righthanded-hitting catcher owns raw power potential in an age when home runs are harder to come by.

Prospect-laden trades cannot be fairly judged until years down the road, but the eventual verdict on the all-important Hamels trade may very well ride on the success or failure of Alfaro's bat, whether he sticks at catcher, mans first base, or plays the outfield.

Alfaro, who could miss the rest of this season because of a left-ankle injury suffered June 10, hit 18 home runs in 113 games across three levels as a 20-year-old, and 17 long balls over 121 games in high A and double A as a 21-year-old. On Friday, he instantly became the Phillies' best power-hitting prospect, although, like most young sluggers, he needs to improve his approach and cut down on his strikeouts.

"Clearly, when you are talking about a premium position-type player, someone who could be a very good offensive player, who can work behind the plate, that's a pretty key element," Phillies general manager Ruben Amaro Jr. said after the teams announced the trade on Friday. "He and [outfielder Nick] Williams, clearly, on the offensive side of the deal were very, very important to us. We view them as premium prospects.

"Now the risk is, the biggest risk, really, is not so much in the injury, but how these guys will continue to develop and what they might be able to do here in Philadelphia. That's the risk, because they're prospects. But . . . they're guys we think are going to impact our club, hopefully in the near future."

A fair estimated time of arrival for Alfaro to reach the major leagues is 2017, especially considering his injury came in his 49th game of what would have been his first full season in double A. He was en route Friday to Philadelphia to visit with Phillies doctors. It's likely he will continue to rehabilitate his surgically repaired ankle at the team's minor-league complex in Clearwater, Fla. Fans may not get their first glimpse of him until major-league spring training next year.

"We know the information, have all the information from the Texas folks about his injury," Amaro said. "We felt comfortable that he's going to be fine. . . . But we don't think it's going to be a long-term issue because it was an acute injury. I think actually he was leading off second base, and I think he just twisted in a weird way."

The risk in Alfaro stems more from his catching and overall rawness behind the plate. The Rangers found him as a 16-year-old infielder in Colombia five years ago and gave him a $1.3 million signing bonus. While he is said to have improved defensively and owns a cannon for an arm, he is far from a finished product. He has yet to log even 100 games in a season at catcher, appearing in a career-high 90 last season and 86 the year before.

There are questions whether Alfaro will remain behind the plate. Regarded as super-athletic, Alfaro could end up in right field if not at first base, one rival evaluator suggested. Amaro made sure to point out Friday that the Phillies acquired him as a catcher, though the GM left the door open.

"The beauty of Alfaro is that this guy can swing the bat, is so athletic that he can play another position if the catching thing doesn't work out," Amaro said. "But he's made great strides over the last few years, particularly with his work behind the plate."

Alfaro was twice named to the Futures Game, although he did not play in the 2013 exhibition after breaking his left hand just days before. This past spring he participated in his first major-league spring training, suiting up in Surprise, Ariz., as Texas' third-youngest player, behind Gallo, a third baseman/outfielder, and second baseman Rougned Odor.

Before his ankle injury, Alfaro was hitting .253 with 15 doubles, two triples, and five home runs for double-A Frisco. He struck out 61 times and worked just nine walks over 190 at-bats. Thirty-six of his 49 appearances came behind the dish, while 12 were as a designated hitter and the other as a first baseman.

A power hitter at a premium position such as catcher would be an extremely valuable asset for any major-league club. But whether it's behind the plate or elsewhere, the Phillies, on pace to hit the second-fewest home runs in the majors this season, need to hit on Alfaro's bat.