"It wasn't enough," Koehler said. "I had a chance early in the game to shut them down. We had a lead, and I let them back in the third. Too many pitches early on. When you walk that many guys and throw that many pitches, your defense gets on their heels, and your team kind of gets into a lull. It's hard to have a lot of energy after that."
That pretty much summed up the day for Miami, which dropped two of three in the series after winning on Monday.
Koehler walked five, one intentionally, and struck out four.
"He seemed to struggle a little bit early, but as he got going, he got better and better," manager Don Mattingly said.
In the third inning, the Phillies capitalized on first baseman Justin Bour's error on David Lough's grounder. Cesar Hernandez reached on a bunt single, on a play Koehler felt he could have been quicker on, and perhaps got the out at first.
"He got down the line really fast," Koehler said. "I thought I made a good throw. I guess I popped up a little bit instead of just stepping and throwing from there. It's on me. It's an out right there. Who knows what could have happened."
The Marlins bullpen has been taxed, and Koehler's seven innings meant just one reliever was used on Wednesday.
Miami is off on Thursday before opening a weekend series with the Nationals at Marlins Park on Friday.
"I felt like after the third inning, my last four innings, I felt really good," Koehler said. "I felt I was more on the attack. That's something I need to do from the beginning."
Joe Frisaro has covered the Marlins for MLB.com since 2002. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.