He seldom pitched until his senior year, but his 94 mile-per-hour fastball caught the attention of a scout for the Cardinals, who made him their first round draft pick in 1982.

In 1987, he became the first pitcher to start his career with back-to-back 30-save seasons, and he made seven appearances in the playoffs that year, as the Cardinals lost the 1987 World Series to the Minnesota Twins in seven games.

He was throwing up to 94 miles per hour (mph) his senior year, when he caught the attention of Steve Flores, a scout for the St. Louis Cardinals who attended a Biola game to watch Tony Woods of Whittier College play.

Flores was impressed with how hard Worrell threw, and the Cardinals selected him in the first round of the 1982 Major League Baseball (MLB) draft.

[5] His ERA was lower (2.09) in eight games (seven starts) with the St. Petersburg Cardinals of the Single-A Florida State League, where he had a 3–2 record, 33 strikeouts, 24 walks, and 41 hits allowed in 47+1⁄3 innings.

[13][14] In Game 1 of the World Series against the Kansas City Royals, Worrell relieved John Tudor with two outs in the seventh and runners on first and third.

In the eighth, he nearly gave up a home run to George Brett, but Andy Van Slyke caught the ball at the fence, and Worrell earned the save as the Cardinals won 3–1.

[17] However, he joined Hod Eller and Moe Drabowsky as the only pitchers to strike out six hitters in a row in World Series play.

[18][19] Worrell relieved Ken Dayley to start the ninth inning of Game 6, with the Cardinals leading 1–0 and three outs away from clinching a World Series title.

The leadoff hitter for Kansas City, Jorge Orta, hit a ground ball to the mound that first baseman Clark fielded, then threw to Worrell, who had covered first.

Worrell went on to allow a couple more runners to reach base, then gave up a pinch-hit single to Dane Iorg that won the game for the Royals by a score of 2–1.

[21] On April 10, the St. Louis closer relieved Rick Ownbey with two runners on in the seventh inning of a game against the Cubs, with the Cardinals leading 3–1.

Worrell retired Mike Schmidt and Von Hayes on fly balls without any runs scoring, then threw two more scoreless innings for the save when the Cardinals won 6–3.

[1] Worrell's 1987 season got off to a "poor start," according to the Associated Press; he blew saves in three games in a row from April 29 through May 2 and posted a 10.57 ERA through May 4.

[28][29] Thereafter, he posted a 1.80 ERA in 18 more games through June 10, at which point he had 14 saves, a total only surpassed in the NL by Steve Bedrosian's and Lee Smith's 15.

[30] On September 19, he relieved Joe Magrane in a game against the Cubs with one out in the seventh, the bases loaded, the Cardinals up 5–3, and Ryne Sandberg at the plate.

[31] In the second game of a doubleheader against the Montreal Expos on September 29, Worrell relieved Greg Mathews with no outs in the seventh, runners on first and second, and the Cardinals up 3–0.

He got one out but gave up an RBI double to Candy Maldonado and left the bases loaded before getting replaced by Dayley, who finished the game without letting any more runs score to earn the save.

Worrell gave up a triple to Gary Gaetti that scored both of the runners, but he got Tom Brunansky to fly out to end the inning, then threw a scoreless ninth to earn the save.

Greg Gagne then hit a sharp ground ball and beat the throw to first base for an RBI single that gave the Twins the lead.

[39][40] On April 27, 1988, Worrell relieved Bob Forsch with one out in the seventh inning, runners on second and third base, and the Cardinals clinging to a 2–0 lead over the San Diego Padres.

[43] At midseason, he was a part of the All-Star Game for the first time in his career, throwing a scoreless ninth inning in the NL's 2–1 loss to the American League.

[11] On December 1, he underwent Tommy John surgery, performed by Dr. Frank Jobe, to repair the damage; the recovery kept him out for the entire 1990 season.

[22][53] By 1992 spring training, Worrell appeared to have recovered; manager Joe Torre said his fastball and slider were back to their normal speeds.

Counting his final game of the 1994 season, he threw 26+2⁄3 scoreless innings, a streak not broken until he gave up a two-run home run to Andres Galarraga on July 1.

However, he struck out Tommy Gregg to end the inning, then allowed just one run in the ninth, preserving the lead as the Dodgers won 4–2.

[73] Dating back to September 2 of the previous year, he had a streak of 24 scoreless innings that lasted until Jeff King had an RBI single against him in a 4–2 loss to the Pittsburgh Pirates on May 5.

[75][77] Worrell finished the season with a career-high 44 saves, tied with Jeff Brantley's total for the NL lead and a Dodger single-season record until Eric Gagne had 52 in 2002.

After walking Eddie Williams to lead off the ninth inning, Worrell allowed back-to-back home runs to Joe Randa and Mark Smith as the Pirates rallied to win 4–3.

[73][82] Though he remained in the closer role all year, manager Bill Russell started bypassing him in favor of Darren Dreifort or Scott Radinsky in September.