"We made contact with all the witnesses that we could find, any friends of James, and just interviewing them to see if they have any idea where he might have gone," said Fullerton Police Lt. Alex Bastreri.
His girlfriend's mother, who was the last person to see him on Saturday, wonders if there were some signs she didn't see.
"Did I not see something? Why didn't I look and see what he was wearing? I kind of guessed at what that was, you know, why I didn't I pay more attention? You know, your mind just goes everywhere," said Diana Bock.
Bastreri said a helicopter and an off-road motorcycle were aiding in the search.
"We got out on foot and tried to retrace the possible tracks that he took, although we're not sure of those tracks," said Bastreri.
Family, friends and teammates put up fliers in the Fullerton neighborhood where he was last seen, asking for the public's help to find him.
The 21-year-old was pitching for Santa Ana College. He had just earned a full baseball scholarship at California State University, Long Beach, and was being scouted by a number of major league teams.
Family and friends said the fact that he didn't touch base with anyone before he left was completely out of character.
"He just likes to crack jokes, have a good time, loves living life. I mean, it's totally out of characteristic for him," said Wernke's teammate R.J. Hively. "I'm trying to block out all the negative thoughts right now and stay positive, but it's definitely unlike him to have no one know where he is. I mean, someone always knows where he is at sometime, but I'm definitely worried."
James' father Robert Wernke reached out to his missing son on camera.
"James, please contact somebody. We're worried about you, we love you, and we want you home," he said.
As investigators search through the night, Wernke's family and friends hold on to hope, praying that he will soon be back home.
"This time is a tough time of the day for us, because it's potentially another night that our son's out somewhere," James' father added.
Wernke was described as 6 feet 4 inches tall, about 190 pounds, with short blond hair and blue eyes. He was wearing gym clothes at the time of his disappearance.
According to family and friends, Wernke left without his keys, ID or wallet. They believe he has his cell phone with him, but it is off and untrackable.
Fullerton police said they have received a number of calls from people in Anaheim, Brea and Los Angeles. However, the sightings proved to be false.
Anyone with information on Wernke's whereabouts was asked to call Fullerton police at (714) 738-6700.