50mg taken now won't have any influence by friday, that's a pretty low dose and enough time for it to leave the body. Tramadol has SSRI properties, or so they suspect at least so yes potentially it could affect a roll. I think I had this once. Took a painkiller from a friend at a festival because my foot hurt. Turns out it's a mixture of tramadol and I believe paracetamol or ibuprofen. I don't have a smartphone on me at festivals so I couldn't research it and just took it. It's called contramal over here. My foot hurt that much that I took more than one and ended up downing 200mg of tramadol in total over 4 hours. That night I rolled, or at least tried to. Took a known 200mg pill (green androids) that I personally tested. Got stuck in that anxious uncomfortable comeup phase for about 3 hours to be left with a nasty hangover for about 12 hours. Ruined my entire night. I am almost certain it was the tramadol but not completely. I did have a bit of a tolerance back then. But in my opinion not enough to have such a big influence
By the way, and I might have said this before, very good track where you got your nickname from