"We feel like we have the potential to add two quality arms and two quality bats to our system," general manager Neal Huntington said.
• Pirates' 12th overall pick: Shane Baz
• Pirates' 50th overall: Calvin Mitchell
• Pirates' 72nd overall: Conner Uselton
The Draft continues on Tuesday with Rounds 3-10. The MLB.com preview show begins at 12:30 p.m. ET, with exclusive coverage beginning at 1 p.m. ET.
The 42nd pick was a compensatory selection awarded to the Pirates after they were unable to sign left-hander Nick Lodolo, last year's 41st overall pick. Lodolo instead honored his commitment to Texas Christian University, where he started 14 games this spring.
Jennings posted a 0.54 ERA with 99 strikeouts in 51 2/3 innings for Dekalb County High School in his senior season. His fastball sits at 89-92 mph and touches 95 mph, and the 6-foot-2, 175-pounder could add more velocity as he develops. The athletic 18-year-old also throws a slider, curveball and changeup. He is committed to the University of Mississippi.
The 42nd overall pick comes with a slot value of $1,635,500, part of the Pirates' overall pool of $10,135,900, the seventh-highest figure in this year's Draft.
Jennings was a two-sport star in high school, as he was named the offensive MVP of his high school district as a junior. Jennings was one of two former football stars picked by the Pirates on Monday, as Uselton was also a promising college football prospect.
"We believe athleticism plays. We believe the best players at the Major League level are athletic," general manager Neal Huntington said. "We love multi-sport athletes because they've done something different than baseball their whole lives; as counter-intuitive as that sounds, it's really important because they still love the game, there hasn't been as much wear and tear with repetitive action and they've learned how to compete differently."
Jennings tore his ACL during a football game last September, ending his football season. The injury didn't keep Jennings off the mound, however, as he kept pitching while wearing a knee brace.
Pirates area supervisor Jerry Jordan, who previously scouted and signed first-rounders Austin Meadows and Will Craig, was familiar with Jennings' work prior to this spring.
"He aggressively, you would say, rehabbed that knee, but he was ready to go right from the start," Pirates director of amateur scouting Joe DelliCarri said. "All the credit to Steven, all the credit to the people around him. So yes, right from the start, we were right with him, following him right out of the chute."