The Islanders got another piece of business done before the opening of free agency on Tuesday.

Defenseman Alexander Romanov, who is a pending restricted free agent, has signed an eight-year contract extension valued at $6.25 million per year, as an industry source confirmed to The Post.

This contract will ensure the 25-year-old spends the prime of his career with the Islanders, where he has played for the past three seasons following a trade from the Canadiens in 2022.

With Noah Dobson traded over the weekend, Romanov became the highest-paid restricted free agent for the Islanders, making him the top priority for Mathieu Darche to finalize before the deadline on Tuesday.

Simon Holmstrom, Max Tsyplakov, Emil Heineman and Marc Gatcomb are the club’s remaining RFAs.

Romanov had four goals and 16 assists in 64 games this season, averaging 22:18 of ice time.