No issue like others said.
The issue is of another nature: the fabric the shirt is made of. Most sports jersey nowadays are made of a shit material called polyester, which is basically a form of plastic.
Other than causing at least light allergic reactions to most people when worn for an extended period of time, they also "produce" microplastics, which get into your bodily system and also, when you wash them, they go to pollute the water.
Why are microplastics an issue, you may ask? Microplastics are a strong contributor, like other enemy-approved nonsense (i.e. soy which they put in most store-bought foods), in lowering your levels of testosterone among other things. It's one of the reasons why most people nowadays have impairments with their masculinity ranging from being an effeminate herbivore to dysfunctional expressions of masculinity.
If you want to support a team or a player, I suggest getting a blank top in the right colour, and going to a printing shop to print the team logo and/or the player name, etc. Make sure the fabric of this shirt is at least 90% natural such as cotton, linen, wool, bamboo, or similar. It's easier to find cotton. Better if 100% or if the remaining up to 10% is made of another healthy and human-friendly fabric.
Many other synthetic fabric are not human-friendly, and a simple online search can provide a starting point to read research about them. For people with a good sense of touch, you can tell something is wrong because these fabrics feel horrible when you touch them (in most cases).
If you are worried about "sustainability", the pond of sustainability is not as shallow as the enemy makes it. It's not about limiting oneself to nefarious synthetic fabrics, but about how natural fabrics are produced. For example, organic cotton is very sustainable.
