On a day when the Yankees acquired the Atlanta Braves' ace, Javier Vazquez, to be their No. 4 starter, the Mets neared a deal with a converted knuckleballer who is missing a ligament in his pitching elbow. The Mets are on the verge of signing R.A. Dickey, who spent last season in the Minnesota Twins' organization, to a minor league contract, according to a baseball official with knowledge of their plans. He was granted anonymity because the deal has not been completed. A first-round pick of the Texas Rangers in 1996, Dickey, 35, may be the only pitcher in professional baseball who does not have an ulnar collateral ligament, the tissue replaced during Tommy John surgery. He was born without one, or, unbeknownst to him, the ligament disintegrated as he grew up. When the ligament's absence was discovered after he was drafted during an examination by Texas' team physician, Dickey defied doctors' expectations by advancing steadily through the Rangers' system and reaching the majors in 2001. A string of poor performances prompted Dickey to reinvent himself as a knuckleballer in 2005, and it was not until he joined the Seattle Mariners in 2008 that he received an extended opportunity. On June 24 at Shea Stadium that season, Dickey pitched seven shutout innings in a victory against the Mets. He was 1-1 with a career-best 4.62 earned run average in 35 appearances (34 in relief) last season with Minnesota before being sent to the minors in early August. 