So how close is he to the show? Assistant general manager Chuck LaMar is reluctant to announce a timetable. But LaMar, the Phillies' director of player development and scouting, agreed that De Fratus is a major league prospect.
"He's a power pitcher, he has a good arm," LaMar said. "He has the velocity, that's not a problem. His fastball is at 97-plus. But against major league hitters, it doesn't matter how fast you throw. You have to develop that second pitch to back the fastball."
The Phils took De Fratus, 23, in the 11th round in 2007. He's coming off an outstanding year (2-0, 1.79, 15 saves in 29 games at Clearwater; 1-0, 2.19, six saves in 20 games at Reading) and was added to the Phillies' 40-man roster. His mission heading into this season was to work on the slider. LaMar saw for himself at a recent outing that it's progressing.
"His slider has been better and he's continued to work with more consistency," he said.
By the way, the Phils still like Aumont, and with good reason. Aumont, 22, has pitched in some hard luck, so his 1-5 record is a little deceiving (he has allowed 15 runs, only eight earned, in 24 games through the weekend). More telling is a 2.43 ERA with 39 strikeouts and only nine walks in 29 innings.
Here's a peek at a few other noteworthy relievers in the Phils' system:
* Lefthander Mike Zagurski remains on that zip line from Philly to Lehigh Valley. He is the IronPigs' closer and has been effective this year with 10 saves and a 1.47 ERA in 18 games through Sunday. But, by golly, he's had quite a few opportunities to get major league hitters out. He has battled injuries (Tommy John surgery, costing him the 2008 season) and, at age 28, hasn't been able to catch on full-time in Philly. Michael Schwimer, on the other hand, can't seem to hitch a ride on that zip line. The 6-8, 240-pound righty has been equally effective (3-0, 1.49, one save) in 23 outings with the IronPigs through the weekend, and has 49 Ks in 36 innings. The Phils got him in the 14th round out if the University of Virginia in 2008.
* Clearwater righty Justin Friend has been perhaps the most effective closer in all of advanced-Class A (1-2, 0.98, 19 saves through Sunday). But . . . he turns 25 next week. Oakland exposed him to the Rule 5 draft after last season following a pedestrian 3-3 with a 3.70 ERA in 36 appearances at Double A Midland. Until this season, his fifth as a pro, he's never had a particularly outstanding year. But . . . word out of Clearwater is that he has a nifty mix of pitches and is said to be a fierce competitor. Late bloomer, perhaps?
* Righthander Eric Pettis was 0-1 with two saves and a 1.23 ERA in 10 games with Lakewood before he was bumped up to Clearwater on May 3. He doesn't seem overwhelmed: 1-0, 0.92 ERA in 11 games with the Threshers through Sunday. Pettis, 23, has no saves with the Threshers, thanks to Friend, but has remarkable control (18 strikeouts, two walks). Not bad for a 35th-round pick last year out of Cal-Irvine. The 6-2, 200-pounder does not have an overpowering fastball, but his location and deceptive sidearm delivery have turned him into a prospect.
* Lakewood righthander Lisalberto Bonilla was named a South Atlantic League all-star last week. Going 0-1 with four saves and an 0.89 ERA since arriving from extended spring training on May 3 is why. He's a 6-1, 164-pounder who just turned 21 and is in his third pro season (the Phils signed him in 2008 as a non-drafted free agent out of the Dominican Republic). He made his first start of the season on Saturday, going five shutout innings, but don't read too much into the starting assignment. Chuck LaMar noted that it's common for pitchers in the Phillies system to work both in starting and relief roles along the way as part of their development.
He was the heralded outfielder who arrived in the trade that sent Cliff Lee to Seattle. Tyson Gillies had been stuck in extended spring training, working out hamstring woes that hampered him throughout last season.
He's back now.
Gillies, 23, was activated from the disabled list Friday and assigned to Clearwater. LaMar said the hamstring problems appear to be behind him.
"He feels fine," LaMar said. "He's 100 percent, knock on wood. We figured he was ready and it was time to let Seabiscuit out of the barn and turn him loose."
Gillies made his season debut at Tampa on Friday, going 0-for-4 with a strikeout. He followed that with an 0-for-5 at Daytona on Saturday, but came back strong on Sunday. He went 2-for-4 with a pair of doubles and a run scored.
A little refresher: Gillies hit .341 with a league-leading 44 stolen bases in 2009 at High Desert, in the advanced-Class A California League. He was viewed as one of the Mariners' top prospects and the Phillies were mighty happy to get him. But the hamstring limited him to 26 games and 105 at-bats last year at Reading, where he hit .238 with just two steals.
So, yes, knock on wood.