"It feels awesome," he said. "It's a great opportunity to be a part of the Astros' organization. I'm just ready to get this thing started."
• Astros' 2017 Draft selections
Papierski, a 6-foot-4 junior from Lemont, Ill., taken with the 271st pick in the 2017 MLB Draft, was named to All-SEC Defensive team and smashed a pair of home runs from both sides of the plate in the College World Series to buoy LSU to the CWS finals June 26-27.
Papierski threw out 23 baserunners attempting to steal The 21-year-old catcher hit .256 in 65 games last season, with 11 home runs, 45 hits and 39 RBIs.
"I can't thank my parents enough for everything they've done, helping me so much through this process," Papierski said. "I want to thank [Astros third baseman and former LSU star] Alex Bregman, too. He helped me my freshman year here at LSU, and now to be in the same organization as him, and get to hang out with him and all of his big league friends, I'm just excited."
"He's an A-plus defensive catcher," Bregman said. "Switch-hitting. Big kid. He's still growing into his body. He's really a steal, to be honest with you."
Bregman, a good friend of Papierski's who played 49 games for the Astros in 2016 and is an everyday infielder for the club in '17, was "fired up" when he was his team had drafted Papierski during batting practice last week.
"My junior year, I slept on his couch," Bregman said. "I lived at his house and kind of got to see what he's all about -- what kind of worker he was. We fit in immediately. All he wanted to do was work on his game, work on his craft and nothing's changed. He's a grinder. He's a great kid and he busts his butt."
"He's probably one of my best friends, and to have this opportunity, to be in the same organization as him, is going to be awesome," Papierski said. "I definitely never would have thought that I would be drafted by the same team as him. Now in the offseason we're going to get to hang out, and hopefully in a few years, I get to hang out with him every day."
While forgoing his senior season at LSU and not signing after Toronto had drafted him in the 16th round in 2014, Papierski's professional career will begin next week.
"Super happy, super happy," he said. "Just happy to get my professional baseball career underway."