Change is inevitable in the modern-day world of baseball, and that hasn’t been lost on Jonathan Papelbon.

When he walked into Fenway Park yesterday, the jersey he sported looked a lot different. His choice of clubhouses was definitely not the same as the one he called home for seven years. Even the song of choice that signaled his entry in the ninth inning now belongs to someone else.

The Red Sox all-time leader in saves, who was back with the Philadelphia Phillies for the first game of a two-game set, knows that the Sox moved on in the year-plus since Papelbon departed via free agency.

He has as well.

“I’ve moved on. Boston was a great city to me and I enjoyed every minute that I had here,” Papelbon said to a horde of media inside the visitors dugout before the game. “I loved it here and I’ve moved on.”

Papelbon’s 219 saves, at an 88 percent success rate, puts him 87 saves in front of Bob Stanley for the most in Red Sox history, and without a consistent, long-term option at closer on this roster, that number seems to be safe for the foreseeable future.

But the 32-year-old Papelbon admitted the young righty who came into the game with a hungry stare and high-90s fastball changed.

“For me I read swings more. I look at swings more and I do a little bit more of that, instead of going out there and saying I’m going to blow it by these guys,” Papelbon said. “I think for me it’s just what I’ve been able to do.”

Papelbon is 9-for-9 in save opportunities this season and his current 172⁄3-inning scoreless streak is second longest among relievers in the National League. Opponents are hitting .159 off him, and his WHIP of 0.64 is the lowest in his career.

In comparison, Red Sox closers have 11 saves in 17 chances, with Andrew Bailey leading the team with six.

“I’ve become more of a complete pitcher,” Papelbon said. “In this game you’ve got to make adjustments. . . . That’s what kind of (will) propel me into the later parts of my career.”

Papelbon wasn’t sure how the fans would react if he did get into a game during his brief stay, but he would be OK with any type of reaction. Just like he’s all right with someone else using “I’m Shipping Up to Boston” for an entrance theme.