I am also a rather introvert person, and it certainly means that I get less speaking practice than I otherwise would. I prefer being with one person at a time rather than in a group, I am not good at initiating small talk with people I don't know (like in coctail parties), and if I have the choice between having lunch in the cafeteria with colleagues or a sandwich in my office browsing the internet, I often prefer the second option. I consider myself lucky not to be in an open-space office. Also at home, when I am with wife and kids, I need a period of being alone - luckily I like to cook, and I don't let anyone into the kitchen when I am making dinner - instead I put on the radio or listen to some Russian pop music.
I have missed som great opportunities to practise Russian because of this. I have Russian colleagues, but so far I have not tried to speak Russian with any of them - I probably would only do so if I were already at a C1 level. I know this is not just about being introvert, but also about having the "courage" to make a fool of yourself
And I could have made Russian acquaintances on holiday several times, but I am not the person to walk up to a stranger and initiate a conversation. I normally stay put with my nose in a book.