The Mets are keeping surveillance across town in their search for a new manager.

With Joe Girardi unsigned beyond this season, and questions looming about his future, the Yankee manager’s name has surfaced in recent discussions by Mets officials in their search for Terry Collins’ replacement, according to a person with direct knowledge of the conversations.

The source added the Mets fully expect Girardi to remain with the Yankees, but have floated various “what if” scenarios. And indications are general manager Sandy Alderson would be open to the idea of Girardi, who has spent the last 10 seasons in The Bronx and led the Yankees to a World Series title in 2009, if he became available.

The Mets have reached out to former Tigers manager Brad Ausmus, as was first reported by Fan Rag Sports, and are expected to speak with several candidates this week. Other potential candidates include Robin Ventura, Alex Cora, Joe McEwing, Kevin Long, Chip Hale, Bob Geren and Sandy Alomar Jr., among others.

The Mets are prepared for a drawn-out, methodical, process that could last beyond the World Series.

Though Girardi would carry a hefty price tag, the Mets could justify it by the amount of buzz such a move would generate. Girardi’s leadership skills are well-respected by the Mets, and Alderson has identified “leader” as the top characteristic he seeks in a manager.

Plus, Alderson has indicated the Mets will not be in a rebuilding mode in 2018, as they look to contend for the postseason, and a manager of Girardi’s ilk might make sense for a team with a “win now” mentality.

As strange as Girardi’s face would seem in the Mets dugout, such a spectacle wouldn’t be unprecedented: Casey Stengel, Yogi Berra and Dallas Green all managed the Mets after previously managing the Yankees. In addition, Joe Torre managed the Yankees to four World Series titles after beginning his managerial career with the Mets.

Ausmus, a former catcher and Dartmouth alumnus — Alderson graduated from the same school — is highly regarded for his intellect, and led the Tigers to a postseason berth in 2014. But Ausmus was dismissed last month after guiding the Tigers to a 64-98 record and last-place finish in the AL Central.

The Phillies could have interest in Ausmus, and the Red Sox might join the mix if manager John Farrell is fired.