This afternoon, Dave Robertson and Andy Pettitte were running the concourse of Citi Field. The concourse.

“It’s fun, something different,” Robertson said. “We kind of got lost a couple of times.”

Tomko and A.J. are the ringleaders among concourse runners. Joba also has joined. Tomko has been running concourses since 1999 when Reds teammate Juan Guzman got him hooked. Some Yankees began to join him during last weekend’s Florida series. Hey, it beats running circles around the field.

“It can be like Groundhog Day during a season,” Tomko said. “This breaks up the workouts; it goes quicker.”

They run in packs of four sometimes. In a 20-minute run, each guy takes the lead for five minutes. He might break up the run with sit-ups or jumping jacks.

“Right in the middle of the concourse,” Tomko said.

“It’s a lot more fun than running,” Joba said. “I mean, it is running, but you can do a lot more things.”

Joba enjoyed checking out Citi Field, which he describes as “nice, very nice.” Said Tomko: “Extremely nice. It has a lot of character.”

As for Robertson and Pettitte, they made it back to the clubhouse after an unplanned detour.

“We were up by the Caesar’s Club (on the fifth of six floors), then almost ran into the press box,” Robertson said. “We weren’t sure where we were, but we figured we should get out of there.”

Nick Swisher: As we were talking to Robertson, Swisher couldn’t help but interject. “Are you asking him why he threw McCann two backdoor cutters?” asked Swisher, wearing a Cheshire Cat grin. “That’s what I want to know.” (Brian McCann of the Braves hit two home runs against Robertson.) Robertson laughed: “Well, the first one was supposed to be a fastball in – and wasn’t. And the second one was supposed to be a fastball away – and wasn’t.” Swisher was highly amused. Robertson’s a good sport. “He hit two bombs off me,” Robertson said. “But I had a pretty good string going of not giving up home runs.” In 16.1 innings, those are the only two jacks Robertson has given up.

Derek Jeter: He’s got to be really sick to miss back-to-back games with the cough/illness that’s going around the clubhouse.

“George!” That’s how Keith Hernandez greets Cone whenever he comes into the YES booth during the Subway Series. We asked Cone why. When Cone was traded by the Royals to the Mets, he often talked about George Brett. So much so, that Hernandez decided to call him George. And probably a few other things. Honestly, as we told Cone, it’s a much more innocent story than we’d anticipated.

Subway Series: Enjoy tomorrow night’s game, the final interleague contest of the regular season. We’ll be watching.