Krasinski mentioned how impressed he was with Barrymore's dedication to Big Miracle in a recent chat with Collider.
"Drew is going to blush, but I really appreciated how professional she was," the actor declared. "I don't think anybody really, fully understands what it's like to be at the level that she's at, and the amount of responsibility that it is."
Krasinski continued: "I'm one of the people that feels very, very lucky to be there, but I've only been doing it for a certain amount of time.
"She's been doing it for longer, and achieving so much more than any of us could even hope to do… [Drew] was always so positive, and it set the tone for the whole rest of the shoot."
Barrymore returned the compliment by revealing that one of the major reasons she signed on to Big Miracle was to work with Krasinski.
"I was so excited about [working with John]. I was like, 'Oh, good'," the actress recalled. "I was so excited about doing this with John because I love his acting and I just think that he's a good person. You believe in that, and it's true."
Big Miracle - which also stars Kristen Bell and Ted Danson - opens on Friday, February 3 in the US and on February 10 in the UK.
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Watch a trailer for Big Miracle below: