PORT ST. LUCIE, Fla. — At some point near the end of spring training, Tim Teufel, the Mets’ third-base coach, will gather the team for a meeting to demonstrate and decode the hand signs they will use this season. One sequence of signs may tell a batter to bunt, or tell a runner to steal, or tell them both that the hit-and-run is on. Teufel has about 10 signs, and he uses his own elaborate system to relay them, just to make the enterprise that much harder for an opponent to pick up on.

Most years, Teufel keeps some of his system the same, tweaking it here and there. But this year, because Daniel Murphy signed with the Washington Nationals in free agency and Bob Geren left to take a coaching job with the Los Angeles Dodgers, Teufel is starting over — the baseball equivalent of changing the locks after a bad breakup.

“The way I do them,” Teufel said, “no one will get them.”

When players change teams, the Mets generally believe, no one is above stealing signs, but Murphy’s situation is somewhat different. Not only does he know the Mets’ inner workings after nearly a decade in the organization, but he also joined the Nationals, the team most likely to stand between the Mets and a division title.

Murphy now appears to be at the center of a burgeoning rivalry. Last year, Washington was the heavy favorite in the National League East, but the Mets, with Murphy helping to lead the way, swept the Nationals twice down the stretch and won the division. After the disappointing finish, the Nationals replaced Manager Matt Williams with Dusty Baker and signed Murphy, hoping he would provide a veteran presence.