Getting older is tough.

You get slower. The knees get creaky. The back requires extensive morning calisthenics to loosen.

And no one wants you anymore.

Just ask James Harrison.

For five seasons, no one was more intimidating or relentless than Harrison on the football field for the Pittsburgh Steelers.

From 2007 to 2011, the outside linebacker had 54 sacks, 27 forced fumbles and one memorable 100-yard interception return for a touchdown in a Super Bowl.

He also has paid the gross national product of Latvia in fines levied by Roger Goodell for his legal bone-crushing and sometimes illegal helmet-to-helmet hits.

Harrison wasn’t a young pup when he emerged as a dominant force in 2007. He already had been in the league since 2002.

Age has caught has caught up to the soon-to-be 35-year-old.

The Steelers released him earlier this month when he wouldn’t restructure his contract. The Ravens had mild interest in Harrison until Elvis Dumervil fell into their laps this week.

Now Harrison is left out in the cold. The Steelers announced Tuesday that they had no interest in re-signing him. They intend to move on, like they have done many times in the past at that position.

Before there was Joey Porter, there was Greg Lloyd, who was jettisoned when he got too old. Before there was Harrison, there was Porter, who also was cut loose.

Now there is Jason Worilds.

It’s hard to doubt the Steelers when it comes time to dump aging vets. Their track record is actually quite good when it comes to knowing when to cut their losses on a player.

Lloyd went to Carolina, had one sack and then retired. Porter had two good seasons with Miami before dropping off the map.

Who knows what will happen to Harrison. I have to believe someone will take a chance on him. He’s not that far removed from his dominating self.

In fact, he showed flashes of the old Harrison this season after he came back from a chronic knee injury with six sacks in 13 games.

But he wanted to be paid as if it were 2008, not 2013.

The Steelers weren’t going to shell out that kind of money for an aging player. They never have.

Harrison called their bluff, thinking there would be more interest in him on the open market than there was. He only found cold shoulders.

It may take until July or August before Harrison signs with someone. It may take a high-profile injury to get him a spot on a roster.

It won’t be in Pittsburgh, however. That’s kind of sad. I’ll miss No. 92, his surly ways, his frowns.

Until the next star comes along. And knowing the Steelers history, he will.