Speaking at a MLB diversity business summit at a convention near Minute Maid Park, Selig praised Houston's rebuilding efforts. He then likened Appel, a right-handed pitcher, and Houston's 2012 No. 1 pick, shortstop Carlos Correa, to two of the franchise's greatest stars, Craig Biggio and Jeff Bagwell.
"The Astros are on their way to building the foundation that every club needs for sustained success and I believe this club has the right people in place to execute their very sound plan that is going to bring winning baseball back to the fans of Houston," Selig said. "I look forward to the day when players like Carlos Correa and a hometown pitcher Mark Appel ... will be among those who form a new core as successful as Bagwell and Biggio were for so many years."
Appel, a polished and well-spoken Stanford graduate, was left speechless when told of the commissioner's remarks.
"That's, uh, it's very nice words that he said," he said, shaking his head. "Just hearing that comparison is pretty special, especially being a hometown Houston guy. Bagwell and Biggio were two of my favorite players and knowing that Bud Selig sees me and Carlos Correa as potentially the next Bagwell and Biggio is exciting."
Terms were not disclosed but Astros general manager Jeff Luhnow said it was "the most significant investment" the Astros have ever made in an amateur player.
The 21-year-old Appel was 10-4 with four complete games and a 2.12 ERA this season. He had 130 strikeouts in 106.1 innings pitched and allowed opponents a .203 batting average.
Appel is an Astros fan who grew up in West Houston before moving to California at the age of 12. The Astros had a chance to draft him last year but instead went with the 17-year-old Correa from Puerto Rico. Appel slid to Pittsburgh at No. 8 last year but turned down a $3.8 million offer and returned to Stanford for his senior season.
Appel said when he rejected the Pirates, he wasn't thinking about potentially being drafted by Houston this season. When it happened, he could barely believe how well everything worked out.
"Growing up in Houston I came to games at the Astrodome and at Minute Maid," he said. "That was the dream. It was every kid's dream to play for your home team and now it's a reality. It's still surreal. I don't think it's sunk in."
The 6-foot-4, 195-pound Appel will be a welcome addition to the hard-luck Astros with his mid-90s (mph) fastball, nasty slider and improving changeup.
"Drafting and signing Mark Appel was a top priority for our organization this year," Luhnow said. "We are an organization focused on winning championships in the future and we expect Mark to be a big part of that effort."
Astros amateur scouting director Mike Elias raved about Appel and believes he will be a key piece in turning around this franchise which has lost 100 games in back-to-back seasons.
"This is what we believe is going to be a high-impact addition to our organization," Elias said. "He is someone who has the potential to be a front-line starting pitcher for a very long time."
Luhnow said that Appel will report to Houston's spring training facility in Florida next week and that he'll likely begin his professional career at short A Tri-City. He expects him to then move to Single-A Quad Cities and possibly Double-A Corpus Christi by the end of the season.
He said he will be at major league camp next season, but that he wasn't sure when he could be pitching in Houston.
"It's too early to speculate on timelines," Luhnow said. "We need to get him out there and get him pitching."