He then spent three years in the military serving in World War II. He returned home safely & made his MLB debut in 1947 as the Giants backup catcher for the two seasons to Walker Cooper.
Westrum was an excellent defensive catcher, with a strong accurate throwing arm. He threw out over 50% of would be base stealers six different times, leading the league in caught stealing twice (1953 & 1954) & coming in second place three other times. In 1950 he led all catchers with a .999 fielding % making only one error in 680 chances, he also was tops in games played (139) & assists (71). From 1950-1954 he was among the top four catchers in games caught, put outs assists & caught stealing every year.
In 1950 he became the Giants regular back stop hitting a career high 23 HRs with 71 RBIs & a .236 batting average. He was never a big hitter, but had a good eye & drew a lot of walks which led to decent on base percentages. In 1949 he posted a .385on base % & in 1950 he drew 92 walks posting a .371 on base %.
On June 24th 1950 he had a three HR game at the Polo Grounds and just missed a fourth HR, which would have been an inside the parker, instead he settled for a triple.
In the 1951 Giants amazing comeback pennant winning season, Westrum hit another 20 HRs with 70 RBIs & 104 walks. Although he hit only .219 he posted a .400 on base percentage. In the 1951 World Series he went 4-17, drawing five walks while playing in all six games. Katt caught over 100 games for four straight seasons, & made two All Star appearances.
In the Giants 1954 World Championship season, he was behind the plate 98 times, while sharing time with Ray Katt. That season he batted a lowly .187, only gathering twelve extra base hits. He drew 45 walks in 246 at bats, hitting 8 HRs with 27 RBIs.
Trivia: On the first Sports Illustrated magazine cover in 1954, Westrum is the catcher behind the plate as Milwaukee Braves slugger Eddie Mathews is swinging at a pitch in Milwaukee's County Stadium.
Post Season: In the World Series against the Cleveland Indians, Westrum batted .273 (3-11). In Game #3 at Cleveland Municipal Stadium, he singled in the 5th inning, driving in Hank Thompson putting the Giants ahead 5-0. In Game #4 he helped the Giants sweep the Series by bringing in two runs in their 7-4 win.
He stayed with the Giants through their last season in New York in 1957 playing in 63 games batting just .165. He was the starting catcher for the last Giants game played at the Polo Grounds on September 29, of that year as a battery mate to Johnny Antonelli.
He retired as a player after an eleven year career, with a .217 batting average, 503 hits, 96 HRs 59 doubles 489 walks & a .356 on base %. Defensively Westrum posted a life time .985 % behind the plate, throwing out 49% of runners attempting to steal.
Westrum did go West with the Giants to San Francisco, being offered the spot of third string catcher or coach. At age 34he chose to coach, a position he held from 1958 through the 1963 season. Then he came back to New York as a coach for the new National League franchise; New York Mets in 1964.
He was one of the first pitching coaches in the game who was a former catcher & not a pitcher. In July 1965 he replaced player/coach Warren Spahn who spent a brief time period with the Mets. In August the aging Mets manager Casey Stengel broke his hip and had to step down from the position due to his health.
Westrum was his replacement & named the second manager in Mets history. He certainly wasn’t the most popular choice but Stengel had promised him the job and held true to his word.
Everyone else expected the job to go to the popular Mets coach; Yogi Berra, who seemed much better suited for the position. Westrum had his problems with the press, early on. He wasn’t an educated man, and they ate him up when he used his malapropisms.
Once as a coach, after a classic Casey Stengel speech, he told the press “boy they really broke the molding when they made him”. Another time after a tight game in St. Louis he said “that was a real cliff dweller". The Mets finished 19-48 under his watch the rest of the way in 1965, once again finishing in last place. In 1966 the team improved to a ninth place finish going 66-95. It was the first time in their brief five year history they did not finish last.
In 1967 Westrum’s Mets went 57-94 falling back to the National League last place spot. But there were a few bright spots, and some hope for the future.
That season the Mets brought up Tom Seaver, who went on to win the Rookie of the Year Award. Ron Swoboda had hit a few dramatic HRs early on & was being billed as a slugger. Tommy Davis hit .302 in his one season in New York, & young veterans Ed Kranepool, as well as Gary Buchek, also put in solid seasons.
Westrum was instrumental in tutoring a young Jerry Grote in his early days as a Met catcher. He helped him not only with tips in catching behind the plate, but also in how to adjust his attitude. In those days, Grote had a real chip on his shoulder, & his manager Westrum said "if he ever learns to control himself, he might become the best catcher in baseball".
He went back to coach for the San Francisco Giants through the late sixties & early seventies. He got another chance to manage in 1974 replacing Charlie Fox. In 1975 his Giants finished in third place one game under .500.
Westrum was replaced by is former battery mate in the Polo Grounds, Bill Rigney in his second go around as Giant manager in 1976. In his managerial career Westrum posted a .415 winning percentage.
He then became a scout for the Atlanta Braves organization. Westrum lived in Duchess County, New York when he played with the Giants. He continued to reside near his hometown of Clear brook, Minnesota where he passed away in 1992 at age 79.