CHARLOTTE -- With the regular season right around the corner, Thursday night's preseason finale marked the last time rookie quarterback Will Grier is expected to see significant playing time in 2019.

It was an up and down preseason for Grier, who has openly discussed his struggles adjusting to the speed of the NFL game. With hopes of finding some positive momentum to carry into the regular season, Grier's night against the Steelers resulted in more of the same, as he finished the night 11-of-18 for 189 yards with one touchdown pass and one interception.

"There are still things I'm learning from," Grier said. "I think it was another good opportunity just to get good reps out there. I feel more and more comfortable every time I get out on the field. Learning the offense more, feeling better, so it's a great opportunity to just keep laying bricks every day."

On his first attempt, Grier completed a quick slant to wide receiver DeAndrew White who turned the short pass into a 54-yard gain. Not a bad start. Grier led the offense all the way down to the Pittsburgh 5-yard line, before Steelers linebacker Jayrone Elliott returned a strip sack 88 yards for a touchdown. Grier bounced back late in the second quarter by capping off a two-minute drill with a perfectly placed fade ball to wide receiver Aldrick Robinson for a 34-yard touchdown.

"They gave us a two man look and the safety hung inside on the seam, so we had a true one-on-one outside," Grier explained. "He ran a great route, got open and made a big-time catch."

Then, just 57 seconds later, Grier was picked off by Steelers cornerback Cameron Sutton, which led to a last-second Steelers touchdown to close out the first half. Grier tried to connect with wide receiver Jadon Mickens, but what he thought was a safe throw wound up anything but.

"It's a hinge-five, basically a comeback, that converts versus Cover 2, but also it converts versus Cover 2 Man, which I didn't know," Grier said. "I just haven't repped it a ton. I've got to know that, and I've obviously learned that. Going forward I won't make that mistake again, and that's kind of what preseason is about. I learned a lesson there."

Grier finished the preseason 34-of-61 for 385 yards with two touchdown passes and three interceptions. Thursday night's 92.1 quarterback rating marked Grier's best of the preseason, beating his previous high of 66.7 against the Patriots by a wide margin.

Grier's improvement didn't go unnoticed by head coach Ron Rivera.

"He did get better today. He did make a mistake, just before half. It was a poor read on his part," Rivera said. "But he made some really good throws today, threw some really nice balls. Gave his receivers chances to make catches for the most part probably with the exception of that one play."

With Cam Newton expected to return before next week's regular season opener against the Rams, and Kyle Allen seemingly ahead of him on the depth chart, Grier's immediate future will be spent in an unfamiliar location. For the first time since transferring to West Virginia and sitting out the 2016 season, Grier will be on the sidelines, not starting. Grier isn't looking at the transition as a setback though, but instead as a chance for him to grow as a quarterback.

"This is an opportunity for me to use every day to get better," Grier said. "Use the reps I get in practice, watch Cam, and just try and get better. All I can do right now for this team is be ready to go if they need me."