Both players are committed to North Carolina and playing for the East. Furthermore, Spain, a 6-foot-5, 285-pound offensive tackle from Charlotte (N.C.) Providence, is rooming with Henderson, a 6-3 quarterback.
"We're all hanging out all the time," Spain said. "We met before but we weren't really good friends before this. But I think we will be after this, for sure. It's huge to have that (relationship), not only for camaraderie, but also for communication and knowing not only him as a person, but how he is as a player so we can play the best we can together. "
Spain will enter North Carolina as a left tackle, but his unselfishness and a numbers issue has him playing right tackle for the East.
"The thing here was everyone wanted to play left tackle, and only a couple of guys said they could play right tackle," Spain said. "I said I would go play right tackle but I can play both sides. It's a little awkward at first, but after a few plays you get used to it with switching your stance and stuff like that."
The East will have its last full practice Thursday followed by a walk through Friday and the game Saturday.
And the preparation for the game is something Spain believes will help when he enrolls at North Carolina.
"It gets you ready for college by going against the best competition you can go against," he said. "It's really fun. It's a great opportunity. It's really an honor to play for the Army. This is, by far, the best competition I've seen. It shows me what my weaknesses are, which can help me as well."
The trip to San Antonio came after the Tar Heels ended their season with a blowout win of Cincinnati, and Spain said knowing he will be on the field the next time North Carolina plays is strange.
"I got to have box seats – we paid for them – but my mom's friend had them and it was awesome," Spain said. "It was weird knowing that was the last game I was going to watch for a long time. I am really excited about it."