Game takes approximately 6 minutes to start up.

Do you mean the game starting or loading your league 

Hello, could you please try removing your cache and preferences folder as shown in the link below.

https://support.sega.com/hc/en-gb/articles/9997644231185

Then, verify your game files (and restart steam) as shown in the link below.

https://support.sega.com/hc/en-gb/articles/9997753543185

If that doesn't work can you please create a support ticket, thank you.

https://support.sega.com/hc/en-gb/requests/new?ticket_form_id=360003117678

Also, I forgot to say. If you are running any custom skin/graphics trying removing them.

Plus, having a large amount of editor files or download team tactics could be causing this.