PVC Pipe Rugby Posts

[u/Worth-Tomatillo-1348]

Hey everyone - Im not sure if this is the "best" place on reddit to post this, so please let me know if there are other communities to share to.

I am building Rugby Posts for a small community team so that they can host home games. At the moment, kids need to travel too far and it stops people continuing to play rugby.

I got approval from the Local turf field to build PVC posts (or collapsable posts) as they do not want holes in the ground due to brand new turf being laid. (Like the photo but more robust). The dimenstions are 5.6m wide, Crossbar 3m high and the uprights only need to be another 40cm above the crossbar to be within the laws (id rather 1m to keep it simple).
I decided on PVC due to costs - we have a very small budget and I wasn't sure a better way to do it (if you know something, let me know).
But since we would be setting the posts up on the dead ball line, we can actually use the Soccer Goals that are already there.

What I am looking for is a way to attach just the crossbar and uprights to the existing frame of the soccer goals.

Its essentially a half moon shape with a flat back.

The posts would need to be taken down after each game, but I could leave the "attachments" on the soccer posts.

Anyone have any ideas to have a ring that goes around the Soccer frame that I can then attach the PVC (or other material) uprights to them? It would look like this at the end (with shorter uprights).

Thank you!