The free agent shortstop played in Baltimore from 2004-07, before being traded to the Houston Astros in December 2007 for five players.
The deal includes around $1 million in incentives for playing time registered, Tejada said.
"I am happy to return to Baltimore, it's like my home," Tejada told Rojas. "We have great young talent, and I think many good things could happen with the club in 2010."
According to The Baltimore Sun, which first reported the story, the deal is pending a physical that's expected to take place in the next couple of days.
"Mentally and physically I was getting ready to play third base since the season ended last year," Tejada said.
Orioles president of baseball operations Andy MacPhail recalled Saturday asking Tejada to move from shortstop during his final year in Baltimore.
"He said he didn't think it was time. He went to the National League after I traded him there and was the All-Star shortstop for two years," MacPhail noted. "So, who's to say Miggy wasn't right?"
Now, however, Tejada appears willing to switch to the hot corner. And MacPhail is confident Tejada will capably handle the position.
"From what I've read, he's made it clear that's something he would entertain," MacPhail said. "He's probably aware that at this point in his career, that's the right move. He's certainly not the first shortstop, if he ends up playing third, that made that change."
Orioles Hall of Famer Cal Ripken Jr. went from shortstop to third in the latter stage of his career and played the position well.
"You don't know until you get there," said MacPhail, who was questioned by reporters at FanFest, a function at the Baltimore Convention Center designed to connect team officials and the players with fans.
Tejada was the first high-profile player convicted of a crime stemming from baseball's steroids era. In February 2009, Tejada pleaded guilty to misleading Congress and admitted he withheld information about an ex-teammate's use of performance-enhancing drugs when questioned in 2005 by congressional investigators.
Tejada was sentenced to probation, 100 hours of community service and a $5,000 fine.
Tejada acknowledged he bought human growth hormone while playing for the Oakland Athletics but said he threw the drugs away without using them, and prosecutors said during his February plea hearing they had no evidence to contradict that.
Through it all, Tejada excelled on the field. Without naming names, MacPhail explained that he never figured his new third baseman would be available this late in the offseason.
"I would be honest with you: I don't know how realistic I thought our potential acquisition was going to be," MacPhail said. "We always had him on the board. But I wasn't holding my breath."
Tejada became a free agent after the Astros declined to offer him arbitration last month.
In 158 games with the Astros last season, Tejada hit .313 with 14 home runs and 86 RBIs. Tejada, 35, is a six-time All-Star and has hit .289 with 285 home runs and 1,185 RBIs in his career.
Manager Dave Trembley said, "I'll say this about Tejada: I don't think there's ever been a guy who wants to win more. He has a very, very strong passion to win. Guys on the team love him. I never had a problem with him. If it works out that he comes back here, I think it would be a real good acquisition."
The addition of Tejada means newcomer Garrett Atkins will spend most his time in the field at first base. Atkins, signed as a free agent in December, can also play third.
"The plan is for me to play first, depending on who else they sign," Atkins said.
The Associated Press contributed to this story.