"I feel like I lost my son," Hammel said Friday after posting a quality start in the Cubs' 3-2 loss to the D-backs.
Hammel held Arizona to one run on four hits and three walks over six innings, but the D-backs rallied to tie the game in the eighth on Paul Goldschmidt's RBI single and then won it on Yasmany Tomas' walk-off single in the ninth.
Hammel, who is coming off a season in which he was 10-7 with a 3.74 ERA, had enjoyed being matched with Schwarber.
"We worked together all spring and it was great," Hammel said of the young catcher/outfielder. "I feel terrible for him. It's such a tough break. I was feeling pretty lucky last night when they said sprained ankle. When you go back and look at the replays, his knee was in a pretty bad place. Hopefully he'll have a quick recovery and we'll welcome him back. Hopefully he'll be sticking around and hanging around with us as he goes through the long process of rehab. It's a tough loss."
Instead of analyzing video of the game, Schwarber was on crutches Friday.
"He was laying it all out there for us," Hammel said of the freak play when Schwarber was injured as he tried to run down Jean Segura's ball. "He's going to be missed."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings. You can follow her on Twitter @CarrieMuskat and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.