Simple timer start and stop from console
Why aren't you inheriting from Timer it's not a sealed class and is disposable (and I believe must be disposed).

public class PokerTimer : Timer
{
    public PokerTimer() : this(2000)
    {

    }

    public PokerTimer(double interval) : base(interval)
    {
        AutoReset = true;
        Elapsed += OnTimedEvent;
    }

    protected override void Dispose(bool disposing)
    {
        //clean up anything you need to here or remove this override.
        base.Dispose(disposing);
    }
}


All that being said, you said this is for a game where you want to time out players so you might want to look a bit into game loops and managing state in such a loop.