Versatile Scarlets back Shingler will partner Cory Allen in the Possibles midfield with big brother Aaron lining up in the Probables back row.
But while family bragging rights are certainly on the line, 22-year-old Steve, who featured eight times this RaboDirect PRO12 season, has plenty more to think about as he bids to earn a spot in the Wales squad to travel to South Africa, having toured Japan last summer without winning his first senior cap.
"It will be the first time we've played against each other. I played against the Scarlets once for London Irish in the LV= Cup, but Aaron didn't play that day," Steve told the South Wales Evening Post.
"My father has been joking that Aaron is going to get me, but I remember when we got the sumo suits out on my 18th birthday and it ended in Aaron having to go to hospital and have stitches in his head. It got a bit tasty!
"It's a great opportunity. It's probably the closest I will get to playing for Wales and I'm going to put everything on the line. You have been able to feel the edge in training this week, especially among the younger boys who are in the camp for the first time.
"It would definitely raise a few eyebrows to beat a side with experienced Test players and Lions squad members in it. It would put pressure on the selectors and I think that is what they want. They want us to perform well and question the front-runners.
"It's been a good experience so far, but it doesn't count for much in training if you don't perform in the game. The excitement is building, the nervous energy is there and I think it's boiling up nicely for Friday."
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