The 24-year-old, who has never played in the big leagues, has been in the Cardinals' system since he was 17.
Now, Solano is impressing Guillen and the staff as he tries to win an Opening Day roster spot.
A non-roster invitee, Solano is in contention for the utility infield job. The team also is considering Donnie Murphy, who is under contract and on the 40-man roster, and Nick Green, a non-roster invitee with big league experience.
"He's in the mix," Guillen said of Solano. "He's playing very, very well. He's doing everything we've asked him to do. He's been great on the field and hitting. He's opening a lot of people's eyes here, especially mine, and my coaching staff. We're going to put him in the mix, and see what happens."
Solano is 9-for-22 (.409) in 11 Grapefruit League games.
One reason why Solano signed with Miami is because Martinez, a shortstop, was sent to the White Sox to help complete the hiring of Guillen in Miami.
Basically, Solano was added to replace Martinez's role in the system.
"I'm trying to prove my talent, and open eyes," Solano said. "I'm just playing the game. I'm having fun.
Solano is striving to make the big leagues for the first time.
"We've got two weeks to decide what we're going to do," Guillen said.