"He just says be yourself and don't try to overdo it," he said.
Clemens, the son of seven-time Cy Young Award winner Roger Clemens, has plodded through five full seasons in the Astros' Minor League system, changing positions from third base to catcher to first base, all while dealing with the expectations of being the son of a baseball legend.
He's never been considered among the team's top prospects, but Clemens' hard work and dedication has put him on the door of making the Major Leagues. The 23-year-old was among the players not on the 40-man roster that the Astros invited to Major League camp last week.
Clemens remembers the moment when Astros general manager Ed Wade called him and told him he'd be in the big league clubhouse for the first time as a player.
"My heart hit the floor," he said. "I was extremely excited and almost ready to go to Florida that second."
It was then Clemens had to take a deep breath and remember his dad's sage advice: Don't try to overdo it.
"Trust what got you there," he said. "He said, 'You're just as good as any of those guys in the locker room, and don't be overwhelmed.'"
Clemens was drafted in the eighth round in 2005 -- the year the Astros went to the World Series with Roger Clemens leading the league in ERA at 42 years old -- and has made a slow progression through the system. He was taken as a third baseman, then played catcher for two seasons, saw some time in the outfield and last year played exclusively at first base.
"I felt more and more comfortable as the season went on and when I went to the [Arizona] Fall League," he said. "I would still expect to be playing first base when I go to Spring Training. We haven't talked about anything else, so I expect to be working at first base and trying to make my way that way."
Clemens got a taste of life as a Major Leaguer on a few occasions last year when manager Brad Mills invited him to play in some Grapefruit League games. He even hit a home run off reliever Matt Lindstrom during an intra-squad game while his dad watched close by.
"That day when I got invited to that game, I was super amped up," he said. "I just kind of calmed myself down and was able to have that good game, and that made me realize that even when the best of the best are there, it's still a game. You have to go out there and play hard and trust yourself."
Astros position players won't have their first workout in Kissimmee, Fla., for another month, but Clemens has been preparing for quite sometime. He's been keeping his arm in shape and is doing cardiovascular exercises daily.
Clemens, 5-11, has been working out with his father with the goal of keeping his weight between 200 and 205 pounds, and he's been taking ground balls on the baseball field at his old high school, where brother Kacy Clemens is now on varsity.
"I'm doing ground balls and long-tossing and doing some weightlifting," he said. "I really am going as hard I can possibly go right now [lifting weights], because during the season we lift just to try to maintain and we're not worried about putting muscle on."
Clemens has shown plenty of muscle at the plate. He was named Most Valuable Player at Double-A Corpus Christi last year after hitting .241 with 26 homers, 85 RBIs and a .350 on-base percentage. The year before, he hit 22 homers and led the organization with 121 RBIs at Class A Lancaster.
"I always joke around when people ask my favorite position, and I tell them it's the batter's box," he said. "I'll do whatever it takes to get in the lineup."
Clemens was told by Wade he wasn't coming to camp to make the team, but the chance to impress in front of Mills and his staff was still important. He'll likely begin the season at Triple-A Oklahoma City and will be a phone call away from reaching the Majors.
"You definitely want to try to impress everybody, but you have to remember what got you there -- playing your game and mentally not worrying about the stuff you can't control," he said. "You go up there and try to make a good impression and play hard and good things will happen."
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.