BALTIMORE -- The Orioles are expected to promote highly regarded pitching prospect Kevin Gausman to make Thursday's start at Toronto, with the organization believing that the 22-year-old right-hander, currently with Double-A Bowie, is its best option.

A source confirmed the likely promotion to MLB.com on Tuesday night.

Gausman -- the O's No. 2 prospect, according to MLB.com -- will likely make his Major League debut on one extra day of rest, earning a promotion that would come sooner than expected but not as a complete shock, given the struggles of Baltimore's starting rotation.

Entering Wednesday, the Orioles had received three consecutive starts of six innings or more, but prior to that, the club endured a seven-game stretch in which it got five innings or fewer from its starter six times. The O's have already used 10 starting pitchers, and Gausman would be taking the turn of Jair Jurrjens, who allowed four runs over five innings in his one start before being optioned on Tuesday.

Manager Buck Showalter said on Tuesday afternoon that T.J. McFarland and Jake Arrieta were the two primary candidates for that start, but it's now expected to be Gausman, who struck out a career-high 10 batters for Bowie on Friday night. Gausman allowed one run on four hits over six innings in that 90-pitch outing and has a 3.11 ERA this season for the Baysox, with 49 strikeouts and just five walks in 46 1/3 innings.

The Orioles' first-round pick -- No. 4 overall -- in the 2012 First-Year Player Draft, Gausman has allowed 21 runs (16 earned) on 44 hits this season. He is considered the organization's second-best pitching prospect, behind only Dylan Bundy, who is currently hurt. Gausman was impressive in big league Spring Training, staying much longer than expected and fitting in exceptionally well among teammates in his first Major League camp.

The Gausman promotion was first reported by FOXSports.com.