"This has taken place through a lot of conversation, but most importantly it centers around the way Edwin came into camp," Farrell said. "He reshaped his body. He's a 13-14-pound lighter baseball player, and that has allowed his mobility and footwork to really advance and be improved over a year ago.
"We feel like it gives us the best defensive alignment on the field."
Encarnacion appeared in 95 games at third base for the Blue Jays in 2010. When he signed a one-year contract during the offseason, though, the club made a point of saying his days at the hot corner were over -- except in emergency situations.
Toronto brought back Encarnacion to receive regular at-bats at DH and backup Adam Lind at first base. That decision came in part because of the 18 errors Encarnacion committed at third last season.
During the first few weeks of camp Encarnacion began his transition to first base. On March 9, though, Farrell announced that the club would consider using him as a backup at third, and Encarnacion started expanding his work in the infield.
Fast forward 20 days and Encarnacion has done enough to make Farrell decide that he is ready to start there on a regular basis.
"Edwin's ability to come in and show us that range," Farrell said. "It goes back to coming in the shape that he's in. We wanted to take a look at this with some games at third base, and we felt going forward that we can take advantage of Jose's arm in right field. We feel that he'll affect the control of the running game."
Bautista tied for second in the American League with 14 outfield assists in 2010. Those numbers came despite the fact that he started 45 games at third.
There had been lots of talk generated by the media and the fan base that Bautista's preference was to play in right field. That was one misconception that he wanted to clear up when Farrell's announcement was made.
"I never said I prefer [right field]," Bautista said. "I always said that I think I'm more valuable to our team defense, as we were set up, in right field, and I still believe that.
"Like I said when they moved me to third, I'm willing to do whatever the manager and the front office thinks is best for the team."
The club approached Bautista on Monday with its decision. Despite the short notice he doesn't feel like it will be a difficult transition back to the outfield.
"I'm more comfortable making the switch from the infield to the outfield, than from the outfield to the infield, when it's something quick like that," Bautista said.
"I usually don't have problems moving from one position to the other. It's just doing it multiple times in a short period of days. That's where my arm gets tight, just from changing arm angles constantly."
Toronto unveiled the new defensive alignment on Tuesday afternoon against the Orioles.
Rivera got the start at DH, where he will receive most of his at-bats, but Farrell said that he could envision a scenario where he gets one start each week in left and right field.
"I think it's the best combination of defensive spots, particularly when you can take advantage of Jose's throwing arm," Farrell said. "His placement in right field makes every third base coach make a decision rather than running at will."