Wales international Wilson, who signed a new long-term contract with the Reds before moving to Pride Park for the 2018-19 campaign, was absent as the Rams suffered a 2-1 loss at The Den.
But Derby boss Lampard does not believe the issue to be serious.
"We were missing Harry Wilson with a small muscle injury, a problem with his groin, and hopefully he will be back soon," Lampard told Rams TV.