I may be wrong here, but I don't think the Besiktas result matters if Liverpool draw as they would go out anyway. As it stands, Liverpool and marseilles are level on 7 points. A draw would put them both on 8 points, but Marseilles have beaten Liverpool and therefore have a better head to head record. So unless Besiktas were to win, a draw between Liverpool and Marseille would see the French team go through as group runners up?
Edit: Just found this on the BBC website: Put simply, if Liverpool beat Marseille in their final group game then they will definitely go through. If they lose they will definitely go out. Complications arise should Liverpool and Marseille draw. Marseille beat Liverpool at Anfield earlier in the campaign, meaning they would edge the Reds out on the basis of that result, assuming Porto beat or draw with Besiktas in the group's other match.
But if Liverpool and Marseille draw and Besiktas pull off a shock by beating Porto, the Reds would go through. In this scenario, Liverpool, Marseille and Porto would all be on eight points. Liverpool would go through with the best goal difference in the head-to-head matches between the three teams.
That may explain it better
