Toronto's manager hasn't tipped his hand on which pitcher will get the promotion from the Minor Leagues for Saturday's start against Kansas City.
"Not yet, but that will be made well in advance of Saturday," said Farrell, who later added the decision has not yet been made internally.
The Blue Jays have only needed a fifth starter once in the first two weeks of the season. That came in Cleveland, where Joel Carreno allowed four runs in six innings of work.
Carreno will once again receive consideration for the opening, but is tentatively slated to start for Triple-A Las Vegas on Wednesday. If Carreno goes ahead with that outing, he will not have enough time in between starts to pitch in Toronto.
Other candidates include Drew Hutchison, Jesse Chavez and, to a much lesser extent, Brett Cecil. Left-hander Aaron Laffey also seems like an unlikely candidate because he was demoted on Friday and needs to wait a full 10 days before being recalled, unless someone on the 25-man roster goes down with an injury.
Chavez might normally have been considered a longshot, but Farrell went out of his way to praise the 28-year-old right-hander during a pregame scrum with reporters on Tuesday afternoon.
"He would be a candidate, and the fact is he's done a very good job of maintaining his stuff over the course of five-plus innings in the times that he's pitched," Farrell said of Chavez, who has posted a 3.94 ERA in 16 innings with Las Vegas. "He was a starter earlier in his pro career, then got shifted to the bullpen -- and there was a realization of his stuff creeping up in terms of its power.
"But it's been very encouraging to see that he's been able to maintain that 92-95 mph that he's shown while at Vegas. He's done a very good job going to a starter's role."
Chavez has spent parts of four seasons in the Major Leagues, but has never started a game at that level. He is 6-10 with a 5.36 ERA in 152 2/3 career innings while striking out 116 and walking 59.