The combination of where he was selected in the draft and who he was selected by made certain that expectations for Thomas as a rookie would be incredibly low. The Cardinals not only have Carson Palmer entrenched as the team's starter, they also Drew Stanton as the established veteran backup.
Thomas didn't slip down the draft because of a lack of talent. He was once considered a top prospect because of his physical tools, but a lack of consistency on the field in college hurt him.
Landing with Arians in Arizona is really the perfect spot for the 23-year-old. He has the prototypical skill set that Arians looks for in a quarterback: He is a big-bodied, tall pocket passer with a strong arm who understands how to alter his throwing motion in tight pockets.
For at least one season, Arians can work on developing Thomas behind the scenes to try and remedy his consistency concerns.
The former Pittsburgh Steelers offensive coordinator and Indianapolis Colts interim head coach has a track record with quarterbacks that is worth boasting about. He has worked closely with Peyton Manning, Ben Roethlisberger and Andrew Luck to great success. With that in mind, Arians should feel confident of developing Thomas into a franchise quarterback, so long as Thomas proves that his skill set translates well to the NFL.
Thomas set about doing that during his preseason debut against the Houston Texans.
No nerves were apparent for Thomas' first throw of the game. He dropped back in the pocket and completed a deep out route to his receiver for a first down. This was a first-read throw, but Thomas began his throwing motion before the receiver came out of his break.
This, combined with his velocity, allowed the ball to get to the receiver just before the defender could break on it. It wasn't a perfectly accurate throw, but he crucially threw it outside of the receiver, where the defender had no chance of reaching it.
A few plays later, on his second pass attempt, Thomas again threw to a receiver running an out route for a first down. This time, he threw an inaccurate pass that forced the receiver to make an impressive adjustment. Pivotally, he let the ball go early again with good velocity so the defensive back never had a chance at the ball.
This arm strength and willingness to throw with anticipation on this kind of route is very important, even if his accuracy is still inconsistent.
If you have lesser arm strength and don't let the ball go early, the chances of an interception multiply. The defensive back has to react to the movement of the receiver and jump in front of him if he wants to get to the football. This isn't an easy feat to accomplish for the defender, so he must rely on poor play from the quarterback to have enough time to get to the ball.
Thomas' physical talent has never been in question, so throwing out routes effectively shouldn't come as a surprise to anyone.
Concerns over Thomas aren't even about his ability to read defenses and work from the pocket. This is something he showed he has a talent for on the same drive against the Texans.
Before the snap, the Texans are showing Cover 4 in the secondary with both safeties deep and both cornerbacks in off coverage. Meanwhile, in the front seven, the defense is threatening to blitz with the slot cornerback shaded inside the slot receiver and the linebackers walking forward.
Even though both safeties are deep, one is slightly closer to the line of scrimmage than the other. Importantly, that safety is lined up to the tight end's side of the field.
When Thomas gets the ball, the safety who initially lined up closer to the line of scrimmage immediately runs forward. He angles towards the tight end, but the tight end stays in to block. Meanwhile, Thomas is watching the deep safety, as the defense now appears to be in Cover 3.
Thomas keeps his eyes on the deep safety until he gets to the top of his drop. At that point, he turns his shoulders to the far sideline. Thomas is a little tentative with his movement at the end, but by keeping his eyes downfield initially, he has held the deep safety in the middle of the field.
Importantly, Thomas never drops his eye level. This is something that most rookies struggle with early in their careers, as they can't help but react to pressure. There is pressure closing in on Thomas as he turns to the far sideline, but not enough to stop him from throwing the ball.
Thomas has a relatively quick release for a man of his size.
At first glance, the end result that is his throw appears to be off target. However, when you watch the play more closely you see that the ball lands in the perfect spot for his receiver to make a reception down the sideline. For some unapparent reason, that receiver misjudges the flight of the football and doesn't run through his route.
This play was negated for illegal contact, but that flag was thrown over the middle of the field. Thomas' receiver cost him a touchdown here because his pass landed exactly where it should in that situation.
William Powell was Thomas' deep threat against the Texans. Powell wasn't creating a huge amount of separation behind the defense, but he was proving capable of getting in behind. Thomas nearly found him for a huge touchdown later in the third quarter when he slightly overthrew him on an impressive pass.
As Powell attacked the deep secondary, Thomas also created a good relationship with Brittan Golden running underneath routes. Thomas found him on multiple slant routes before a well-placed pass on an out route gave the offense a first down.
In this game, Thomas proved that he could throw the ball effectively to every area of the field. Two of his most impressive plays came when he threw the ball between 10 and 20 yards down the field.
At this stage of the game, Thomas had shown off that he could read the defense from the pocket, throw accurately under pressure from the pocket, throw to every area of the field from the pocket and get rid of the ball quickly through mechanical means or by throwing with anticipation.
The only thing left for Thomas was to show that he could work outside of the pocket. That's exactly what he did for his touchdown pass.
Thomas' pump fake on this play was reminiscent of Ben Roethlisberger, who is able to sell his pump fake because he can push the ball so far away from his body without losing control of it in one hand. Thomas does it in traffic here, before keeping his eyes downfield as he leaks into the pocket.
By finding his open receiver over the middle of the field, Thomas showed off the awareness and poise that play-extending quarterbacks in the NFL need to have.
Although he will need to prove himself against a greater level of competition, only one major question mark remains for Thomas moving forward. Unfortunately for him, that question mark is the same one that followed him through the draft process: Can you be consistent?
At this stage of the season, Thomas can't prove his consistency. He can only prove his talent. He has certainly ticked all the boxes in that area.