DiPietro's surgically repaired knee swelled up late Sunday, hours after practice. He visited a doctor Monday morning and he is out indefinitely, according to media reports.
DiPietro said the medical visit was precautionary.
"It's like anything, you fear the worst and hope the best and this is as close to the best as possible," DiPietro told reporters. "This is a big thing we're battling back from here and we don't want to do anything foolish to ruin all the hard work we've put into it."
DiPietro missed the first three months of this season rehabbing his knee. He returned to action in January.
ESPN.com NHL writer Pierre LeBrun contributed to this report.