The abduction Wednesday night was the first known kidnapping of a major leaguer in a country that has dozens of players on big league rosters, and it has brought a renewed focus on rising violent crime in Venezuela.
Deputy Justice Minister Edwin Rojas said investigators were making progress in gathering evidence and had physical descriptions of the kidnappers based on the accounts of witnesses.
"We have faith in the quick resolution of this case," Rojas told state television. He said President Hugo Chavez's government "is working 24 hours a day to solve this case."
Armed men seized Ramos at gunpoint outside his home in a working-class neighborhood in the city of Valencia. Authorities said Thursday that they had found a stolen SUV used by the kidnappers abandoned in a nearby town. Police spread out searching for clues in the area.
Venezuelan security expert Luis Cedeno said Ramos' abductors probably belong to one of the country's highly organized criminal groups that focus on high-profile kidnappings, and are likely to demand a large ransom.
"It's a very sophisticated, well-planned kidnapping," said Cedeno, who leads the Venezuelan organization Paz Activa, which monitors crime issues.
He said judging from previous cases, the ordeal might last months. In one case last year, banker German Garcia Velutini was freed after more than 11 months in captivity, following negotiations and what police said was payment of an unspecified sum.
In such high-profile kidnappings, Cedeno said, the abductors are generally "men who carry out one or two kidnappings a year and they plan it very, very well."
"The motivation is totally economic, so it wouldn't make much sense for them to kill the player," Cedeno said, though he noted that in some cases it has happened.
Neighbors held a candlelight vigil Thursday night outside Ramos' home and prayed for him, as did fans at a baseball game in Valencia.
At games in three Venezuelan stadiums Thursday night, players and fans observed a minute of silence. Some held signs reading: "Free Wilson Ramos!"
Teams added green to their uniforms, some sporting a green ribbon on one shoulder, others a green "W" for Wilson embroidered on their jerseys.
Katherine Vilera, a spokeswoman for Ramos' Venezuelan team the Aragua Tigres, posted a message Friday morning on Twitter saying: "The kidnappers haven't made contact. All that's left is to be patient, pray and have faith."
In Washington, some fans held a vigil Friday evening outside Nationals Park, the stadium where Ramos' major league team plays.
Someone posted red signs reading "Free No. 3" -- a reference to Ramos' uniform number. The gathering was organized by fans via social media sites such as Twitter.
A total of 87 Venezuelan played in Major League Baseball during at least part of the last season, and some return in the offseason to play with Venezuelan teams.
Security has increasingly become a concern for Venezuelan players and their families as a rising wave of kidnappings has hit the wealthy as well as the middle class.
Bodyguards typically shadow major leaguers when they return to their homeland to play in the winter league, though it was unclear what precautions if any Ramos was taking while at his family's home.
Major League Baseball officials said it's the first kidnapping of a major leaguer they can recall.
Ramos' agent Gustavo Marcano said the catcher, who had returned to Venezuela after his rookie season, was just outside the front door of house with his father and two brothers when the SUV approached with four men inside, three of whom got out and seized the player.
Polls consistently show rampant crime as Venezuelans' top concern. The country has one of the highest murder rates in Latin America, and the vast majority of crimes go unsolved by authorities.
Venezuelans tend to blame societal and bureaucratic failures for the crime problem, which existed long before Chavez was elected in 1998. Still, Ramos' kidnapping could become a political issue for Chavez, who is up for re-election in October 2012.
The country's opposition coalition said in a statement that Ramos' abduction is another sign of Venezuela's unchecked violence, adding that the underlying cause is "this government's negligence."
Chavez's government has created a new national police force and in 2009 passed a revised law that stiffened prison sentences for kidnapping.
Even so, the number of kidnappings has soared in recent years. In 1998, just 52 kidnappings were reported. Last year, police said there were 618 kidnappings reported in 2009.
Cedeno's organization cites other figures showing there were 895 abductions reported in 2010. He and other security experts say the real number of cases is actually much higher because many abductions are never reported to authorities.
Relatives of several Venezuelan major leaguers have previously been kidnapped, and in two cases have been killed.
In 2009, the mother of former major league pitcher Victor Zambrano was rescued in a commando-style operation three days after she was abducted. A cousin of Zambrano had been kidnapped a few days earlier, and was later killed.
The mother of two-time All-Star pitcher Ugueth Urbina spent more than five months in captivity until she was rescued in early 2005.