Connie Marrero in an undated photo. (The Washington Post)

Connie Marrero, a diminutive Cuban pitcher who was a fan favorite with the Washington Senators in the early 1950s and who was the oldest surviving former major league baseball player, died April 23 in Havana. He died two days before his 103rd birthday.

His death was confirmed by Kit Krieger, a Canadian baseball fan who had befriended Mr. Marrero and had spoken with his relatives in Cuba. Mr. Marrero had suffered a stroke several months ago.

By the time Mr. Marrero joined the Senators in 1950, just before he turned 39, he was already a pitching legend in Cuba. He had led the Cuban national team to three amateur world championships in the 1930s and 1940s and was known throughout the Caribbean island nation.

Unusually small for a pitcher, the 5-foot-5 Mr. Marrero was known for his good-natured humor and for smoking gigantic Cuban cigars. Sportswriters dubbed him “Conrado the Conqueror,” the “Cuban Perfecto” and a “muscle-bound little gnome.”

Mr. Marrero was one of several Cuban players with the Senators in the early 1950s, and he might have been considered something of a team mascot if not for his talented right arm and his acumen on the mound. During his five years with the Senators, he kept opposing batters off-balance with an assortment of sliders, curveballs and knuckleballs that danced and darted across the plate.

Cuban-born pitcher Connie Marrero of the Washington Senators poses before a game in 1951 against the New York Yankees at Yankee Stadium. (Diamond Images/Diamond Images/Getty Images)

“That guy throws you everything except the ball,” Hall of Fame slugger Ted Williams said in 1951, the year Mr. Marrero was named to the American League All Star team and was featured in Life magazine.

Mr. Marrero’s age was always a matter of conjecture, and at times the Senators shaved four to six years off his birthdate. In 1952, the Saturday Evening Post noted that he was “positively thirty-five, absolutely thirty-seven, indisputably forty-three, and definitely forty-two.”

Yet through guile and grit, Mr. Marrero managed to win 11 games for the woeful Senators in 1951 and 1952. He finished in the top 10 in the league with a 2.88 earned run average in 1952 and had a remarkable 16 complete games in 22 starts. He was positively and indisputably 41 at the time.

Even though he didn’t throw hard, Mr. Marrero had a sneaky delivery that defied description.

The Dominican-born Felipe Alou, who was a star major-league player and manager, once said, “Connie Marrero had a windup that looked like a cross between a windmill gone berserk and a mallard duck trying to fly backwards.”

First baseman Eddie Robinson, who was briefly Mr. Marrero’s teammate in 1950, struggled against him after he was traded from the Senators.

“He had a big leg kick, which was a little bit deceptive, and a good little slider and pinpoint control,” Robinson, a four-time All Star, recalled Wednesday in an interview. “I always had trouble against him. I don’t think I hit .200 off him.” (Robinson’s average against Mr. Marrero was .175.)

Mr. Marrero last pitched for the Senators in 1954, finishing with a career record of 39 wins and 40 losses and a creditable 3.67 ERA. Decades later, he could recall the exact pitch sequences he used to strike out Williams, Mickey Mantle, Joe DiMaggio and other superstars.

In Cuba, Mr. Marrero kept pitching until he was almost 47 before he turned to coaching. He became a mentor to younger pitchers such as Livan Hernandez, who played for the Washington Nationals and other teams during a 17-year big league career.

“In Cuba, everybody knows this guy,” Hernandez told The Washington Post last month. “He’s like the god of pitching.”

Conrado Eugenio Marrero Ramos was born April 25, 1911, in the rural Sagua la Grande district along Cuba’s northern coast.

He grew up working on a sugar plantation and playing baseball. He was an infielder before becoming a pitcher in his mid-20s.

Mr. Marrero led Cuba’s national amateur team to world championships in 1939 and 1940 before losing to Venezuela in 1941 in a game that became renowned in both countries. The next year, when the teams met again, Mr. Marrero shut out the Venezuelans, 8-0.

He played for professional teams in Cuba and Mexico before signing with the Senators in 1947. Assigned to Washington’s minor league club in Havana, Mr. Marrero won 70 games in a three-year period and recorded sterling ERAs of 1.66, 1.67 and 1.53.

He continued pitching with Cuban teams through the winter and, in one 12-month period in 1947-48, threw 455 innings and won a remarkable 37 games.

Mr. Marrero was known to pray at Cuban religious shrines to keep his arm healthy, but when he was asked years later about his longevity, he quipped, “I smoke these cigars to keep my arm young.”

He had several children and grandchildren, but complete information about Mr. Marrero’s survivors could not be confirmed.

Although Mr. Marrero was not overtly political, he remained loyal to his Cuban homeland. He did not receive a major league pension until Krieger, who leads baseball tours of Cuba, and former players helped secure an annual stipend for Mr. Marrero in recent years.

In 1999, when the Baltimore Orioles traveled to Havana to play a Cuban national team, an 87-year-old Mr. Marrero was invited to throw out the first pitch. He didn’t stop at just one and beckoned the Orioles’ Brady Anderson to step up to the plate.

Years earlier, when he was still with the Senators, writers asked Mr. Marrero what he threw to get opposing hitters out.

“Everything but my cigar,” he said.