Ryan Kartje (LA Times) —  When Courtland Ford stepped in as USC’s left tackle this past spring and never left, it appeared that the biggest question mark along a questionable Trojans offensive line was answered.

Ford was the only freshman lineman to start a game last season and the first called upon to replace first-round draft pick Alijah Vera-Tucker in April. His future as USC’s left tackle seemed all but assured.

Ford remained in that role to open fall camp Friday. But by Day 2, that seemingly sealed left tackle competition looked wide open.

It was Jonah Monheim (above), not Ford, who stepped in as USC’s first-team left tackle Saturday, signaling that the battle to be the blindside protector is not as won as it once seemed.

“We’ve got an open competition right now with the starting offensive line,” new USC offensive line coach Clay McGuire said. “Jonah, Courtland, [Jalen] McKenzie and [Andrew] Vorhees and [redshirt freshman] Casey Collier, we’ve got guys that are all competing for those tackle spots right now.”

Whether Monheim will keep hold of that role is anyone’s guess. McGuire and offensive coordinator Graham Harrell assured Saturday that they would continue to mix and match linemen in different positions. But both made a similar promise in the spring, only for Ford to spend the entire session solidified at left tackle.

Even as Ford took hold of the role then, Monheim earned effusive praise from coaches over the spring as the Trojans’ second-team right tackle. The hyperbole started with USC’s head coach, as Clay Helton suggested at the time that “Jonah may have had the best camp of anybody on our football team.”

That camp, Monheim said, was crucial in building his confidence.

“I felt a jump in spring, and I’m hoping to keep building on that right now,” Monheim said. “I think that just comes from mental processing, being in the scheme, understanding defensive schemes. I’m just feeling quicker, feeling a little faster.”

He and Ford might both wind up starting  –  if McGuire holds to his promise of competition at both tackle spots. McKenzie, a senior right tackle, struggled at times last season and could be in jeopardy of losing his job if Monheim and Ford continue to impress. On Saturday, McGuire said he believes all three tackles could “play at a really high level.”

“The trick for us is really to figure out which of the two are the best ones,” McGuire said.

Ford stated his case for one of those two spots over the summer by focusing on rebuilding his body.

“I felt like it changed me totally,” Ford said of USC’s offseason training program. “I feel more control of my body. It’s just more technique and being able to have the repetition. I’m strong enough and powerful enough to sit back and anchor anything.”

It’s still undecided whether he will be the one anchoring the Trojans’ maligned offensive front. But after spending most of the spring in front, Ford doesn’t seem to be backing down from the prospect of a competition.

“I love it,” Ford said. “There’s no spot locked down, so it’s a grind every day, knowing I’m fighting for a starting spot. The motivation inside of me is going to be push me every day. Because I know I have a job to win.”