Being a capable fighter wasn't the only criteria for someone that Sam would want to have at his back, but they had enough common interests here for it to do in a pinch. He certainly trusted Daryl more than he trusted Meg, and Meg considered herself a member of Team Sam. She also compromised Cas somewhat, though Sam still trusted the angel. However he looked at it, their numbers had fallen significantly, and it wasn't a good time for that, not when bombs were being dropped and triggers being pulled.
"Well, you already teamed up with Jo once, yeah? To get rid of the gremlins." Sam had noticed that, because he kept track of Jo. It had been the first he'd noticed of Daryl even being here. "Sure, I'll meet Rick."
He lowered the water and rolled his shoulders back, easing the tension in them. The warmth in his muscles felt really good; so did the calmness in his mind. The fight had eased him up enough to say, "I'd say you should meet my brother, but he's been sent back."
Of course, if Daryl paid any attention to the SHIELD announcements, he probably already knew that. Even if he didn't tell people that Dean was his brother, their last names were the same; he figured Daryl was smart enough to put two and two together. The way he spoke might have suggested otherwise, and Sam wouldn't have taken him for an intellectual type, but that didn't mean he was stupid, just like having correct grammar didn't make a person smart. Generally it was safer to assume people knew things about him, anyway, considering how much information about him there was available.