Even with starting left tackle Ronnie Stanley and center Tyler Linderbaum, it’s hard to predict if the Ravens can build a solid offensive line this season.

The Ravens opened the preseason Friday night losing to the Philadelphia Eagles, 16-13, at M&T Bank Stadium, and there was enough optimism to see development, but enough negativity that might cause problems as well.

Let’s just say the outcome was a draw, or about as even as the Ravens finishing with 82 passing yards and 82 rushing yards against the Eagles.

Overall, the group turned in a solid effort considering Stanley, the ninth-year player out of Notre Dame, was held out and Linderbaum couldn’t play because of a “soft tissue” injury.

Offensive line play is about timing and rhythm, and after last season, the Ravens lost both starting guards, John Simpson and Kevin Zeitler, as well as starting right tackle Morgan Moses.

Both coach John Harbaugh as well as offensive line coach Joe D’Alessandris knew it was going to take some time to rebuild the front five, and it showed against Philadelphia.

When the game mattered most in the first half, the pocket was fairly clean for backup Josh Johnson, who started in place of star quarterback Lamar Jackson.

Johnson had ample time to throw, but the 38-year-old struggled either because of his own errant passes or his slow progression in processing coverages. The Ravens worked some of their combination blocks well, especially 6-foot-8, 380-pound right guard Daniel Faalele and 6-6, 360-pound center Ben Cleveland.

Second-year left guard Andrew Vorhees, who missed his rookie season because of a torn ACL, is eventually going to be a top player and has strong mechanics. But it was easy to tell that this group doesn’t have the timing down yet. For one, they missed Linderbaum because centers usually set the slide protection. There were times when the Ravens were late in identifying blitzes or were so involved in their blocks that they couldn’t recover fast enough to slow the Eagles.

Faalele has great size, but there are still questions about his conditioning as well as hand placement and pad level. Cleveland played well Friday, which was somewhat surprising because he had only been the starter at the position for the previous five practices.

Right tackle Patrick Mekari is the most technically sound offensive lineman on the roster and he took most of the repetitions with the first unit in the first half, but there are still questions about his mobility and recurring back problems. Those are the same concerns about Stanley, who has had several season-ending ankle surgeries in recent years.

Rookie right tackle Roger Rosengarten, the team’s second-round draft pick, rotated with Mekari on Friday and is still an unknown.

Right now, the offensive line is easy to read. Josh Jones, who started in place of Stanley, tilts to his left or leans back on his heels on passing plays. Faalele takes a big split from the center on obvious “draws” or leans forward heavily on running plays.

If it’s noticeable by the media from the press box, opposing defensive coaches and coordinators will see it after watching tape.

But remember, it was only one preseason game. The Ravens have two more before they open the season Sept. 5 against the defending Super Bowl champions in Kansas City.

Will there be a dramatic difference by then?

Probably not. It can take as many as four games to work out all the nuances of strong offensive line play. It didn’t help that both Linderbaum and Stanley were on the sideline, and the Ravens had some players out of position.

Cleveland was a guard at the University of Georgia. Faalele played tackle at the University of Minnesota. It doesn’t sound like much of a difference, but it’s a new world.

A year ago, Ravens offensive coordinator Todd Monken said his unit was a work in progress. A year later, the offensive line is in the same position.