At no point, Leyland said, did Jackson lose consciousness. Leyland quickly signaled for rookie infielder Danny Worth to enter as a pinch-runner.
"He was pretty dizzy right away," Leyland said. "He came around pretty quickly, but that's one of those things where you just don't take chances."
Jackson remained on the ground for a couple minutes before he was helped up to his feet. He walked off the field under his own power as Rand led him back into the clubhouse. Teammates Gerald Laird and Brandon Inge said Jackson was alert and talking in the clubhouse before he was taken to Huntington Memorial Hospital in Pasadena, Calif., for precautionary tests.
"I saw him in the dugout, and then I saw him before he left," Laird said. "He said he was fine. It's a scary moment."
Teammates said two factors likely contributed to the situation. The first was the time of day. The game was a 4 p.m. PT start, and the sun was setting around that inning. Several Tigers players said it was difficult to follow pitches amidst the shadows falling over the ballpark.
"That backdrop was really tough to see," Inge said. "A 4 o'clock game, it's pretty crazy here."
Said Leyland: "If you looked at all the hitters late, it was tough to see. At that time of day yesterday, they were having a hard time in batting practice seeing the ball."
The other factor, Inge said, was a curveball Troncoso had thrown to Jackson earlier in the at-bat. It was far enough inside that Jackson backed away before it broke back. It was still inside, but Inge said a pitch like that puts the thought into a hitter's mind to hang in longer on an inside pitch rather than backing away. By the time Jackson reacted to the fastball a few pitches later, it was too late.
The Tigers took it as an accident, a pitch that just got too far inside.
"You had a guy throwing pretty good, and it was pretty tough to see at that time of the day," Leyland said. "It's just one of those unfortunate things. They happen. It's all part of the game."
Regardless of the test results, Leyland said he won't play Jackson on Sunday. Combined with Monday's scheduled off-day, that'll give Jackson two days off before the Tigers open a two-game series at Seattle on Tuesday night.
Jackson, acquired last December from the Yankees in the Curtis Granderson trade, has been a catalyst atop the Detroit order after making the team in Spring Training. The 23-year-old entered Saturday batting .333 with 11 doubles, three triples, a home run and 11 RBIs, while stealing six bases in seven attempts. He has played exemplary defense in center field.
As he lay on the ground Saturday, however, the Tigers' lineup was the least of the team's worries.
"You don't like to see that to any player, especially your own, but any player," Leyland said. "That's scary for all players."