Joba Chamberlain attempted to be the first Yankee to welcome Kevin Youkilis to The Bronx yesterday when he phoned the third baseman with the likely intention of clearing the air. The initial try resulted in Chamberlain leaving a voice mail for Youkilis, who officially will become a Yankee when he passes a physical. He accepted the Yankees' one-year offer for $12 million Monday to fill in for Alex Rodriguez. Considering their history, Chamberlain and Youkilis have something to talk about. Though Chamberlain has hit Youkilis with a pitch just once — this past season when he was with the White Sox — Chamberlain has thrown up and in numerous times on the former Red Sox. In 2007, Chamberlain threw two fastballs over Youkilis' head, and Chamberlain was suspended for two games. A season later, Chamberlain sent Youkilis to the dirt, and Youkilis responded by going toward the mound but was restrained. ? Mariano Rivera is confident he will be ready for Opening Day. "I don't see why not,'' Rivera said about being healthy by April 1, when the Yankees open the season against the Red Sox at Yankee Stadium. "We have three to four months to that point. I will be ready.'' With Rafael Soriano a free agent, the Yankees are counting on Rivera to take his customary place among the elite closers in baseball. After Rivera's 2012 season ended on May 5 due to a knee injury suffered shagging batting practice fly balls that required surgery, the Yankees brought Rivera back on a one-year, $10 million deal that represented a $5 million pay cut. Since the mid-June surgery to repair a torn ACL in the right knee, Rivera has been working to strengthen the hinge. "I don't want to give the [percentage]. I don't want to speculate, but I am feeling good,'' Rivera said after participating in the Yankees' annual food drive at the Stadium. "The leg is getting stronger and stronger. You have to give it time. I am doing my part and time is doing its part.''