- Bats Left, Throws Left
- Height 5' 10", Weight 150 lb.
- High School Booker T. Washington High School (Memphis)
Mathis debuted in 1940, going 2-1 and hitting .194 as an outfielder. He again went 2-1 in 1941 then was 8-7 in 1942. That year, he was second in the Negro American League in wins, behind Gene Bremer. His 3.53 RA placed him 5th behind Jack Matchett, Booker McDaniel, Satchel Paige and Bremer. In the second 1942 East-West Game, he relieved Bremer with a 5-2 deficit in the third and allowed four hits and two unearned runs in 3 1/3 innings while striking out two. He went 0 for 2 at the plate. Alvin Gipson wound up relieving him. Verdell had gotten 123,657 votes for the East-West Game that year, third among pitchers behind Satchel Paige and Hilton Smith.
The Arkansas native split 1943 between Memphis (6-1; .250) and the Philadelphia Stars (4-2), his only time pitching for a team other than the Red Sox. His 3.63 RA for Memphis was 4th in the NAL behind Gentry Jessup, McDaniel and Sug Cornelius. In 1944, the 29-year-old was 9-9 and batted .310. He started for the West in the 1944 East-West Game and got a no-decision in their 7-4 win; he allowed one run on three hits in three innings and also singled off Terris McDuffie.
Lefty was 8-10 in 1945 but still tied Jim LaMarque for 5th in the NAL in wins and was 5th in strikeouts (81). He again got the call to start for the West in an East-West Game and threw three shutout innings in the 1945 East-West Game, walking one, fanning four and giving up no hits in a 9-6 win. At the plate, he went 2 for 2 with a run. Jessup relieved him. After the season, he had surgery to remove bone chips and he never would be as effective on the mound.
Mathis was on the preliminary ballot in the 2006 Special Committee on the Negro Leagues Election.
- The Complete Book of Baseball's Negro Leagues by John Holway
- The Biographical Encyclopedia of the Negro Baseball Leagues by James Riley
- Black Baseball's National Showcase by Larry Lester