"It's been a very, very long time since I've been able to walk on knees that felt good," Eflin said. "So I'm excited."
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The Phillies are hoping that Eflin's improved health will lead to improved results on the mound.
Eflin joined the Phillies in December 2014 in the Jimmy Rollins trade with the Dodgers, immediately becoming one of the organization's top pitching prospects. He made his big league debut June 14, allowing nine runs in 2 2/3 innings against the Blue Jays, but he recovered to post a 2.08 ERA in seven starts from June 19 to July 22.
Then something happened. Eflin had a 13.85 ERA in his next three starts before landing on the disabled list with bad knees.
It is perhaps surprising that Eflin did not have the surgeries earlier.
"Before surgery, it was almost like a cramping feeling," he said. "Just walking around and stuff. I couldn't really get down, pretty painful. It just got to a point where every day it really started to bug me and kind of hold me back a little bit.
"It's just night and day, man. There's really no pain at all, and if there is, it's after a very long day of doing my [rehab] and it's just soreness. It's nothing that's going to affect me. That's the exciting part. I'm able to get down and still use my legs with the little amount of soreness that's still there."
Eflin declined to say how much his knees might have affected him on the mound, although he obviously pitched with success in the Minor Leagues and during that seven-start stretch last summer. But he said he feels a significant difference in his stride to the plate.
"When I'm coming down with my [left] leg, I'm actually able to get some weight loaded up on my back half and exploded through and throw," Eflin said. "So instead of standing like a two-by-four out there, I actually feel like I have some leverage and am actually able to get something behind the ball."
Eflin will need to pitch well to crack the Opening Day rotation. Jeremy Hellickson, Clay Buchholz, Jerad Eickhoff, Vince Velasquez and Aaron Nola are favorites, if not locks, although Nola is coming back from a right elbow injury.