SAN FRANCISCO -- Circle the calendar. Justin Verlander’s return date has finally become clear.

Verlander threw three innings and 43 pitches in a simulated game Sunday in Port St. Lucie, Fla., taking a significant step forward in his return from a right teres major strain. He is lined up to make a Minor League rehab start on Friday and, assuming everything goes well with that, debut for the Mets the following week in Detroit.

If Verlander remains on a five-day schedule, as he has throughout the most recent portion of his rehab, he will debut May 3 against the Tigers. That could push to May 4 if the Mets give him an extra day of rest.

“He went out there and got after it a couple pitches toward the end,” Mets manager Buck Showalter said of Verlander’s simulated game. “He looked good.”

Verlander’s next outing could come for the Single-A St. Lucie Mets in Clearwater, Fla., according to Showalter, though the long road trip across Florida may prompt the Mets to make other plans. Alternate options include a game for High-A Brooklyn at Jersey Shore, or Double-A Binghamton at home.

After that, Verlander should debut. He won’t require a second rehab outing, per Showalter, though the Mets may need to keep his pitch count limited in his first start back -- possibly in the range of 75 pitches as he stretches out to a regular starter’s workload.

“He’s anxious to get back,” Showalter said.

Whatever Verlander can give the Mets, they will take, particularly considering the current state of their rotation with Max Scherzer suspended and José Quintana and Carlos Carrasco both injured. Scherzer is due back on May 1, potentially restoring both the Mets’ aces to active duty in a three-day span.

That would end more than a month-long rehab for Verlander, who landed on the IL on Opening Day after undergoing an MRI. Initially, Verlander classified his muscle strain as minor, saying he “definitely” would have pitched through it in a postseason scenario. Later, Verlander called a late-April return a worst-case scenario.

But the Mets have been cautious with Verlander, whom they signed to a two-year, $86.6 million contract in December. He is coming off a Cy Young season in which he went 18-4 with a 1.75 ERA over 28 starts for the Astros, but he’s also 40 years old and less than three years removed from Tommy John surgery.

In Detroit, Verlander will pitch against his original team, for whom he played from 2005-17. Verlander won a Rookie of the Year Award, an MVP and the first of his three Cy Youngs with the Tigers.