Terrion Arnold’s NFL debut hasn’t gone as planned.

He broke coverage that led to a long touchdown against Tampa, has been flagged three times for pass interference inside the 5-yard line, and currently leads the NFL in penalties as he heads into Week 3 against the Arizona Cardinals.

After missing two consecutive practices, the first-round pick was back on the field Friday and seems on track to play in Arizona.

“Today’s a big day for him,” said head coach Dan Campbell. “He did walk-throughs, is feeling better, so we’ll see how he looks running around in practice. But he’s trending in the right direction.”

Despite early struggles, the Lions believe Arnold is improving. He’s allowed 11 of 13 targets to be caught for 129 yards and has been flagged four times for 82 yards, both league highs. Those penalties have led to 13 points.

Arnold also seemed to be at fault on a 41-yard touchdown pass to Chris Godwin after broken coverage.

However, the Lions remain confident in the 24th overall pick.

“I have full confidence in him, and I’m fine with him learning during this process,” said defensive coordinator Aaron Glenn. “He’s going to be a great player for us.”

Second-round pick Ennis Rakestraw (hamstring) also returned to practice Friday, while linebacker Alex Anzalone (brain) and guard Graham Glasgow (knee) practiced for the second consecutive day. Both Anzalone and Glasgow are expected to play in Arizona.

Safety Ifeatu Melifonwu (ankle) was the only player not dressed for Friday’s practice. The Lions have considered moving him to injured reserve but are hopeful he’ll return within the first month.