Ji-Man Choi ready to show off his quirks

When a ball skips past him in pregame warmups, he laughs. When a pitch is called a ball that might actually have been a strike, he smiles.

Ji-Man Choi’s next at-bat will be his first in the major leagues, and it should not take long for the Angels reserve first baseman to become known for his unusual antics.

The 24-year-old South Korean is one of the more demonstrative major league players in recent memory.

“I do it on purpose,” Choi said through interpreter Jae Park. “I just want to confuse the pitchers.”

American baseball customs are far more subdued than in Choi’s home country, where professional players often flip their bats to celebrate home runs.

Choi, a Rule 5 selection, won a spot on the Angels’ 25-man roster despite a so-so spring at the plate. He flashed power and on-base skills but also a penchant for striking out.

The Angels tried him in left field several times in the spring and his defense there was worrisome. His abilities at first base are clearer, but Choi is on the team to hit more than anything else. He scrapped switch-hitting in the spring and will bat left-handed as an Angel.

In parts of five minor league seasons, he has hit .302 with a .404 on-base percentage and .481 slugging mark. And he reacted outwardly throughout his rise up the minor leagues.

“By showing expression, I’m able to see how pitchers will throw the ball,” Choi said. “That’s the main reason why I do it.”

Wilson a ‘B-plus’

C.J. Wilson said he passed all but one of the strength tests the Angels training staff conducted over the weekend. His resistance to force at various arm angles was examined and measured.

“I guess I got like a B-plus on it, not an A-plus, and they want me to get an A-plus before they let me loose,” he said. “It’s progress.”

Because of shoulder tendinitis, the 35-year-old left-hander has not thrown off a mound in more than three weeks and has not thrown at all in about two weeks after sitting out the final two months of last season. Once he is cleared to resume a throwing program, Wilson said, it will take at least him a month to return to the majors.

Wilson will use an altered delivery from what he most often employed during six prior seasons as a starting pitcher. In the spring, he described it as “completely different.”

Monday, he was more conservative with his description.

“It’s not going to be like Joe Smith,” he said ,referring to the Angels’ sidearm reliever. “But it might be more like [Andrew] Heaney. Just a little bit lower arm angle, a little bit more across my body. It’s all conceptual at this point, though.”

The little throwing he did with this delivery was comfortable, Wilson said.

During last week’s Freeway Series at Dodger Stadium, Wilson inadvertently tested the arm by throwing a ball to a fan.

“I chucked it up there about 100 feet, so that was cool,” he said. “And then I was like, ‘Wait a second, I don’t think I was green-lit to do that.’”

Short hops

Left-hander Tyler Skaggs, returning from Tommy John surgery, will start the first game of triple-A Salt Lake’s season Thursday at Sacramento. He is scheduled to throw four innings. … Right-hander Jered Weaver will throw a four-inning simulated game Tuesday at Angel Stadium. By Wednesday’s off day, the Angels will determine when Weaver will make his regular-season debut. … Former Angels outfielder Garret Anderson threw out the first pitch Monday.

pedro.moura@latimes.com