Lonnett graduated from Beaver Falls High School and signed with the Phillies in 1948, and spent much of his career with the Phillies as a Minor League Baseball (MiLB) catcher and manager, and MLB catcher and scout. He missed two seasons while serving in the United States Navy in World War II and the Korean War. Lonnett spent four MLB seasons a second-string receiver, appearing in 143 games, while batting .166, with six home runs (HR) and 27 runs batted in (RBI) — never once cracking the .200 level for a season.
When Tanner was traded to the Pirates for Manny Sanguillén — only the second trade in MLB history to involve a manager — Lonnett followed him to Pittsburgh. He wore Sanguillén's No. 35 jersey until the Pirates re-acquired Sanguillén a year later; after which, he wore No. 32. Eventually, Lonnett served as third-base coach on the Pirates' 1979 world championship team.
In the final years of his life, Lonnett battled Alzheimer's disease and was cared for by his wife of 56 years, Alvida. In 2004, he attended the 25th anniversary celebration of the 1979 World's Champs, at PNC Park.
Lonnett succumbed to his long-standing illness, in his home town of Beaver Falls, Pennsylvania, on December 5, 2011. He was 84.[1]