It's an interesting and complicated decision.
Arrieta hasn't pitched since May 7 at Triple-A Norfolk, and he missed his last scheduled start because of a strained right shoulder. He's been throwing in the bullpen and is fine physically.
Arrieta is 1-2 with a 7.31 ERA in three starts in Toronto, with 14 runs (13 earned) and 20 hits allowed in 16 innings. It's not an ideal setup for his return to the Orioles' rotation, where he went 1-1 with a 6.63 ERA in four starts before being optioned, with 16 walks and 20 strikeouts in 19 innings.
Arrieta is the long man in the bullpen again tonight, and he will be eliminated from consideration on Thursday if he needs to cover for starter Miguel Gonzalez, who came off the 15-day disabled list today.
McFarland is a risk because he's never started in the majors and he hasn't gone more than 3 1/3 innings in any of his 10 relief appearances - and that was his first one back on April 6. He hasn't thrown more than 53 pitches in an outing, but Showalter said McFarland probably could give the team 75-90. Later, Showalter said 90 might be "a stretch."
McFarland, chosen from the Indians' organization in the Rule 5 draft, has registered a 2.61 ERA in 10 games. The Orioles must be careful not to shake his confidence if he's moved into the rotation and doesn't have success. Would he be able to slide back into the bullpen and pick up where he left off, with no carryover from his failed starts?
The Orioles chose to option Jair Jurrjens today because they needed length in the bullpen, which Arrieta can provide. As Showalter pointed out, Jurrjens has an option remaining and could return to the team in 10 days.
Outfielder Nolan Reimold, on the disabled list with a strained right hamstring, may travel with the club to Toronto and take early batting practice, rather than report to extended spring training in Sarasota. He would still need to go on an injury rehab assignment.
Catcher Taylor Teagarden, on the disabled list with a dislocated left thumb, could play in his first extended spring training game on Monday.
The Orioles have moved up outfielder Xavier Avery from Double-A Bowie to Norfolk. Baysox outfielder Kyle Hudson was placed on the seven-day disabled list.
Outfielder Henry Urrutia is back in Bowie's lineup tonight after missing the last two games with soreness in his side.