He also was a little surprised.
"I had a feeling that I would go between 46 and 50," the 6-foot-5, 190-pounder said.
Walker, who went 43rd overall, is eager to get his professional career started, saying that he wants to reach the Major Leagues in five years.
"I want to get signed quickly," said Walker, who graduates from high school on Wednesday, two days after being drafted and attending "Grad Night" activities on a boat off the California coast, where he spent most of his time dancing.
Just what kind of kid is Taijuan (pronounced "TY-wan") Walker?
"Nice, caring and very respectful of others," he said.
His high school coach, Jeff Stout, went a bit further.
"He's a mature kid, not real outspoken, kind of a quiet kid, but also like a magnet," Stout said. "Kids are drawn to him.
"He is such a phenomenal athlete and has a great personality. He likes to dance, you know, the fancy things kids do nowadays on the dance floor. He's a very down-to-earth kid."
Walker seemed to be on the shy side during the 15-minute conference call, explaining that he began to realize his pitching potential while playing for the Los Angeles Angels' "scout" team last fall, and is surprised that his fastball has been clocked at 96 mph.
"Maybe the high 80s," he said, "but it feels really good [to throw that hard]."
Though he pitched "a little bit" in Little League, Walker developed into a superb hitter and was a primarily a position player in high school -- until his senior season.
Walker posted a record of 10-4 with a 1.77 ERA as a senior, striking out 93 batters in 67 1/3 innings, pitching four complete games in 14 starts and tossing a no-hitter. He led Yucaipa to the CIF Southern Section Division 2 championship game and allowed just six extra-base hits but no home runs. In his final 10 games, he went 8-1 with a 1.22 ERA and 59 strikeouts.
"He has not had a lot of time on the mound," Stout said. "He pitched four games as junior and won them all, but we had a couple of other pitchers, including Matt Davidson, a kid now with Diamondbacks, so we didn't need to have Taijwan on the mound as a junior. He played shortstop most of the year and was second or third on the team in RBIs.
"Because of a lack of mound time, he has not done a lot of throwing. He has a fresh arm and is loose as a goose. He throws effortlessly, and his ceiling is so high right now. He was throwing 88 to 89 [mph] as a junior and he recently hit 96.
"Does he get to 98 next year?"
Stout, who has been the Yucaipa baseball coach for the past 34 years and now has had 14 of his players drafted, said Walker ranks near the top in a lot of ways.
"I have coached a lot of baseball players," he said, "and Tyrone Hill was probably the best, but I have never coached a better athlete than Taijuan."
Hill, a 6-foot-7, 220-pounder as a senior, was the 15th overall choice -- by the Brewers -- in the 1991 First-Year Player Draft, but arm injuries cut short his career.
"Taijuan would be good in any sport he tried, including golf, hockey and soccer. He is just an exceptional athlete," Stout added. "Those are the kind of guys that, if they can stay healthy, can go a long way, and hopefully have a fast trip."
The first 17 years of Walker's trip have been challenging.
"He's had a tough home life," Stout said.
Walker's parents are divorced, and his mother raised four children.
"Taijuan has gone to a lot of 'showcase' events in Florida and Arizona all by himself, and I think that has helped his maturity," Stout said. "You have a lot of kids where Mom and Dad hold their hand their whole life, the kid signs a contract, goes out and doesn't know how to handle [himself].
"But Taijuan has not had that, and he has come out smelling like a rose, so to speak. Traveling around the Minors will not be that big a deal for him, and I look for him to have success, because he's already been on his own."
The Mariners are expecting the same.
"All we need to do is get him in the organization, make sure he's handled right and develops and stays healthy, and then we'll see how it unfolds," general manager Jack Zduriencik said. "When you're sitting at No. 43 and you have a chance to get a guy that throws 95 with a good curve that's very athletic, [you get him]."
Zduriencik said that Walker "could move at his own pace, but he has a chance to get to the big leagues a little sooner, just because of his age."