Justus Sheffield needed to take a step back to take a step forward.

And that last step comes Friday night, when the left-hander is scheduled to take the mound for the Seattle Mariners when they play host to the Toronto Blue Jays in the opener of a three-game series.

Sheffield (0-0, 6.00 ERA), the centerpiece to the offseason trade in which the Mariners sent James Paxton to the New York Yankees, will be making his first major league start. He made one relief appearance April 26 for Seattle, allowing two runs on two hits and four walks over three innings. He was optioned back to Triple-A Tacoma the next day.

Mariners manager Scott Servais said at the time he'd prefer Sheffield continue to "work on things" rather than move him back and forth between Triple-A and the majors.

"We'd like to call him up and leave him here and let him go," Servais said.

But that's not what happened. Sheffield struggled so mightily at Tacoma, going 2-6 with a 6.87 ERA in 13 appearances with 41 walks in 55 innings, that he was demoted June 14 to Double-A Arkansas to regain his command and confidence.

He regained both, going 5-3 with a 2.19 ERA in 12 starts. In 78 innings, he struck out 85 and walked just 18.

"I feel like I am in a pretty good spot," Sheffield told 710 ESPN in Seattle recently. "When I am on the mound, I just feel good. I had to take a step back but sometimes in life you have got to do that, but I feel like it actually has been a positive step forward for me and I just have to continue to build off where I am right now."

The Mariners had Thursday off after completing a nine-game trip to Detroit, Toronto and Tampa Bay, during which they took two of three games at each stop.

They rallied for three runs in the ninth inning Wednesday in Tampa Bay to take a one-run lead, only to have the Rays score twice in the bottom of the inning for a 7-6 victory. That snapped Seattle's four-game winning streak.

"We played well, and they had to come back and win," Mariners outfielder Mallex Smith told the Seattle Times. "We didn't lose. They beat us."

The Blue Jays have dropped five consecutive games, including back-to-back walk-off losses to the Los Angeles Dodgers, the team with the best record in the majors.

The Dodgers scored three runs in the bottom of the ninth Thursday to win 3-2 after Toronto right-hander Jacob Waguespack allowed just one hit in seven scoreless innings.

The Blue Jays are scheduled to start right-hander Trent Thornton (4-8, 5.30 ERA) in the series opener. Last Saturday, he pitched six innings of three-run ball against the Mariners in his first time facing Seattle (0-0, 4.50 ERA), allowing five hits and four walks while striking out three. He didn't get a decision in a game the Blue Jays lost 4-3.

"He made a big adjustment. He was all over the place, honestly," Blue Jays manager Charlie Montoyo said after that game. "Four walks. He couldn't command any of his pitches. He did find a way to keep us in the game, but then the last two innings, seven outs or eight outs, he made an adjustment."

--Field Level Media