For Mariano Rivera, this February is different. There is no spring training, no regular season in his future and no uniform to put on. He is retired now, and with the Yankees’ spring training in full swing and his home country of Panama set to host a Yanks-Marlins exhibition series next month, Rivera can be forgiven for feeling the small pang of nostalgia during the first February of life as a retiree. “I ain’t going to lie to you. I do miss baseball, but I miss my family, too. I’m fine,” Rivera, 44, said on a conference call Wednesday. “It’s a little different. I’ve been doing (spring training) so many years. But I know exactly what I needed to do. It’s not like I don’t know what I’m doing.