Not missable
Chapter 9: Balls and Beans
Chasing Luca
You'll need to carefully follow Luca. He will be unaware that you are following him, so don't alert him by getting too close. On the other hand, don't stay too far back or you'll lose him completely.
You'll arrive at Clemente's slaughter house and will need to find a way to sneak in. To the right is a sewer entrance, allowing you easy access to sneak by any guards. However, the sewer's bile will leave you with an obvious stench.
You'll need to sneak through the rest of the butchery. However, given your smell you'll need to be absolutely avoid any dog. Their loud barks will alert gangsters to your location, instantly compromising the mission. Make your way passed doors, and duck below counters. You'll soon locate your mafia allies, and they are in a heap of trouble.
Pay Back
Luca will send one of his worst goons after you in a one-on-one brawl. He will do a two hit combo before letting up for a second. Be sure to always dodge two punches before countering with your own. However, once he's heavily damaged the enemy mobster will resort to single heavy punches. Adjust your counters accordingly.
You'll free Tony Balls after the fight, and the two of you will make an escape route for Harvey Beans. Tony is a good shot and will help quite a bit with defeating enemies. However, he never wields anything but a basic pistol. You'll need to arm yourself with a shotgun to take out the tougher enemies.
Luca will call for reinforcements, but they are easily taken out with Tony on your side. However, he seldom moves out of cover, making one or two of the enemy gangsters your priority to get a good shot. After Tony and Beans get there hands on Luca, feel free to poach his car. Since your clothes are still rancid, stop by a clothing store or your apartment to get a change of clothes. With a new pair of threads, head to the waypoint to finally join Falcone's family.
Source:
http://www.gamespot.com/features/6274410/p-11.html