This past weekend, Major League Baseball, and perhaps more importantly, the Detroit Tigers, celebrated Justin Verlander’s final start in baseball.

Verlander had signed a one-year deal to return to Detroit this season, bringing a 21-year career back to where it started. As he walked off the mound for the final time, the stadium stood in honor of his career, and his daughter ran onto the field to hug him.

There wasn’t a dry eye in the house (or the internet).

Verlander won Rookie of the Year, three Cy Young Awards, two World Series championships, and was selected to 10 All-Star teams. He threw three no-hitters. In 2011, he won the pitching Triple Crown, leading the American League in wins, strikeouts, and ERA while posting a ridiculous 2.40 ERA.

By any reasonable measure, Justin Verlander is one of the greatest pitchers ever.

And he ended his career where it began.

In our industry, we call people like this boomerang employees.

The comparison isn’t perfect. Most people don’t leave the office with 40,000 coworkers standing and applauding while their kid runs out of accounting to hug them.

But watching Verlander return to Detroit made me wonder about something much less sentimental:

How many companies actually know where their best former employees are?

Not theoretically.

Is there a list?

Who owns it?

When was the last time anyone talked to them?

Do you know where they work now, what they have learned since leaving or whether they might ever consider coming back?

For many companies, the answer is no.

Which is strange when you think about how much infrastructure businesses have built around every other important relationship.

We have CRMs containing thousands of prospective customers.

We track leads who downloaded one whitepaper three years ago.

We build nurture campaigns around people who visited a website twice.

Recruiting teams maintain databases filled with candidates they have never actually employed.

But someone who spent five years inside the company, understood the business, performed exceptionally well, and left on good terms?

Their email gets shut off, their equipment gets returned, and eventually they become a name somebody vaguely remembers.

That seems backwards.

Companies spend enormous amounts of time building talent pipelines filled with people they don’t know while ignoring a pipeline of people whose work they have already seen.

And those people may be considerably more valuable now than when they left. In fact, ADP shows that 35% of all new hires this year are boomerang employees, perhaps for that very reason.

That and the employee who returns is not the employee who left.

They have worked inside another organization. They have seen different leadership styles, systems, technology, and ways of solving problems. They have probably been exposed to ideas your company hasn’t encountered yet.

They also have something most employees inside an organization eventually lose: comparison.

They know what your company does unusually well because they have seen how someone else does it.

They also know where your organization is making life unnecessarily difficult.

That perspective has value.

But none of it matters if the relationship ended the moment they resigned.

Maybe the better offboarding question isn’t simply, “Why are you leaving?”

Maybe it is:

Would we hire this person again?

If the answer is yes, that person shouldn’t simply disappear into the giant HR bucket labeled “former employee.” They should become part of a deliberate alumni network of people the organization wants to know for the next five or ten years.

An automated newsletter nobody reads.

An actual relationship.

Maybe someone checks in once or twice a year.

Congratulations on the promotion.

Saw that the company you joined launched something interesting.

How are things going?

We’re getting a few former employees together next month if you’re around.

Nothing transactional. Nothing disguised as recruiting.

Just maintaining the relationship.

Because careers are long.

Companies change.

People change.

The employee who wasn’t quite ready to lead a division when they left may be running one somewhere else five years later.

The person who needed experience your company couldn’t give them may have gone somewhere else and gotten exactly that experience.

And the employee who left because there wasn’t an opportunity available at the time may eventually find that the right opportunity has opened.

None of that can happen if every resignation is treated like a breakup.

There is also an important distinction between retention and loyalty that companies sometimes miss.

Retention measures whether someone stayed. Loyalty is whether the relationship survived when they didn’t.

Sometimes good people should leave.

They should take bigger jobs. They should try different industries. They should move across the country. They should go somewhere that can teach them something you cannot.

That doesn’t have to mean the relationship is over.

Justin Verlander left Detroit and became an even greater version of Justin Verlander.

He won championships somewhere else. He reached milestones somewhere else. He played for different teams, learned different organizations, and added chapters to a Hall of Fame career far away from the place where it began.

And then he came back.

Most companies will never have a Justin Verlander walk through their doors.

But almost every company has somebody they wish they could hire again.

Somewhere right now is one of the best employees your company ever had.

They know your business.

They know your people.

They may be significantly better at their job today than when they worked for you.

The question is whether anyone at your company still knows their phone number.