Cubs historical sleuthing: Spring training edition

I came across the photo at the top of this post via this tweet:

Well, you know me. I immediately wanted to sleuth out the date of that game!

You might say, “Hey, Al, a spring-training game from almost 48 years ago? You’ll never find that.”

Ah, so you doubt my sleuthing skills? First, here’s a larger version of that photo.

And, we’ve been given clues from the tweet itself. It’s obviously Ernie Banks, and the tweet says it’s from 1971, Ernie’s final season.