The goalie participated in warmups prior to the 3-2 win at Prudential Center.
When asked if Blackwood had the injury before warmups, coach Lindy Ruff said, "I think it's a combination of maybe dealing with something ... that's a difficult question to answer, so I'll just leave it at that."
Ruff had no further update on Blackwood's status.
Scott Wedgewood made 40 saves in Blackwood's place. Aaron Dell was the backup.
The Devils (10-13-4) have won two games in a row after going 1-7-2 in their previous 10. They play the second of a three-game series against the Penguins on Saturday.
Blackwood is 6-8-1 with a 3.05 goals-against average and .903 save percentage in 15 games. He made 33 saves in a 3-2 victory against the Buffalo Sabres on Tuesday, his first win in seven starts.
He missed six games in January when he was in the NHL COVID-19 protocol.
