Texans coach used to text quizzes to his rookie quarterback who's now lighting it up - and he was never able to stump him

Deshaun Watson was expected to sit and learn for a few weeks this season. Instead, it took him all of two quarters to become the Houston Texans' go-to quarterback.

The rookie quarterback from Clemson was inserted into the lineup in the second half of the Texans' Week 1 game after a dreadful performance from Tom Savage.

Though Watson was only slightly better than Savage in Week 1, the Texans decided to stick with him, and they haven't looked back.

Three weeks later, that decision looks smart as Watson is now lighting it up. In a 57-14 win over the Tennessee Titans on Sunday, Watson threw for 283 yards on 25-of-34 passing, with four touchdowns, one interception, and he added his own rushing touchdown.

Watson has impressed and grown quickly, none of which may surprise Texans coach Bill O'Brien. According to Peter King of the MMQB, O'Brien used to text his rookie quarterback during the offseason with little football quizzes and Watson always had the answer. From King:

"But in the summer, during the time the Texans were off before training camp, O'Brien would throw Watson the occasional text with a quiz, to see how far along he was, and how much he'd studied in the spring and early summer. O'Brien marveled at never being able to stump Watson. Maybe we should have expected this. After all, there's one quarterback in history who's twice thrown for more than 400 yards against a Nick Saban-coached defense. Only one. Watson."

O'Brien told King: "He's seeing a lot of different things - third-down blitzes for the first time, red-area things for the first time. I think he's made some really good decisions. That's the kind of guy he is. He's a very calm guy. He's a very thoughtful guy."

Watson has already connected with older, talented teammates on both sides of the ball.

Wide receiver DeAndre Hopkins said after the game that players should "thank" the Texans for moving up in the draft to select Watson.

"You have to thank the organization for going out and moving up and getting a guy like Deshaun Watson," Hopkins said (via ESPN's Sarah Barshop).

In Week 4, the Texans offense dominated so thoroughly that the defense grew restless about not being on the field. Defensive end Jadeveon Clowney told Barshop:

"We usually play in a lot of snaps on defense, but this game we didn't get to play too many snaps. I think I was on the sidelines like hollering at the coach one time like, 'Man, I'm not on the field enough.' He was like, 'Nobody's on the field right now.'"

Watson's composure and accuracy makes him look like a steady veteran, not a player who was starting his third NFL game:

The Texans' offense looked anemic in the first two weeks of the season, but over the past two weeks, they've scored a combined 90 points, one of which was a 36-33 dual against the Patriots that they lost thanks to a game-winning drive by Tom Brady.

If Watson can remain steady - though surely a five-touchdown performance won't become the standard - the Texans have the pieces to take the AFC South.