He played in Major League Baseball (MLB) as a center fielder from 1966 to 1984, most notably as a member of the Chicago Cubs and the Los Angeles Dodgers with whom he won a World Series championship in 1981.

Monday was born in Batesville, Arkansas, and earned league honors in baseball at Santa Monica High School in Southern California.

He was offered a $20,000 signing bonus by Tommy Lasorda, who was a scout for the Los Angeles Dodgers at the time; however, he was convinced to accept a scholarship to play for Arizona State University, after Sun Devils coach Bobby Winkles, an Arkansas native himself, drew upon their shared roots and promised Monday's Arkansas-born mother that he would take care of her son.

[2][3] Monday joined the Arizona State Sun Devils team that included future major league players Sal Bando and Duffy Dyer.

He singled in his professional debut on June 29 at Bethel Park in Eugene, Oregon,[6] and played his first home game two nights later at Bengal Field in Lewiston.

[7] After the season, he and Bronc teammate Dave Duncan entered boot camp with the U.S. Marine Corps in San Diego in September, serving actively in the Reserve for six months before the beginning of spring training.

At Dodger Stadium in Los Angeles on April 25, 1976, two protesters from Eldon, Missouri, ran into left-center field and tried to set fire to an American flag after the start of the bottom of the 4th inning.

After Ken Crosby of the Cubs threw a pitch that made Ted Sizemore pop out, Monday dashed over and grabbed the flag to thunderous cheers.

[19][20] In the deciding Game 5 of the 1981 NLCS at Olympic Stadium in Montreal, Monday hit a two-out ninth-inning home run off the Expos' Steve Rogers.

From 1989 to 1992, Monday moved farther south to call San Diego Padres games alongside Jerry Coleman, replacing outgoing announcer Dave Campbell.

[27] When Steiner replaced Collins on the road TV broadcasts in 2014, Monday switched over to the play-by-play duties alongside Nomar Garciaparra.