HOUSTON -- Houston Texans offensive coordinator Tim Kelly knows there are some things rookie quarterback Davis Mills will have to learn by doing it in a game.

One is learning that it’s OK to throw the ball away at times instead of forcing throws into tight windows.

“You can have the conversation as much as you want," Kelly said, "but until he goes out and experiences it and makes the mistake and realizes, ‘Whoa,’ I think that’s kind of what really ingrains that philosophy in a player."

Mills experienced that in Houston’s 40-0 loss to the Buffalo Bills (3-1) in Week 4, when he threw four interceptions and ended the first half with minus-23 net passing yards.

“The big thing that we’re continuing to preach with him is that we’ve got to protect the football,” Kelly said. “Can’t have these situations where borderline careless decisions were made. … When we’re starting to force balls and try to do things in tight windows that we really don’t want to do, we’ve just got to eliminate the careless mistakes there.”

Mills said one of the focuses this week in his one-on-one meetings with coach David Culley has been “about making smart decisions with the football."

“It’s never a bad thing to throw a completion in front of the sticks and punt on fourth down and play the field position game rather than trying to force something and making a bad decision with the ball,” Mills said. “[We] talked about that, talked about [how] sometimes incompletions are okay, or throwing the ball away or taking a sack, if the situation fits, to protect the football.”

The loss to Buffalo that dropped the Texans (1-3) to 0-2 in games Mills has started since starting quarterback Tyrod Taylor was placed on injured reserve with a left hamstring injury. This could be Mills’ last start, as Taylor is eligible to come off of injured reserve after missing three games. But early in the week, Culley said the team wasn’t sure exactly when the veteran quarterback will return.

“We’re hopefully able to get him back here in the next couple weeks,” Culley said.

In Houston’s first two games, the Texans ranked seventh (74.2 points) in offensive efficiency, a measure that looks at success on a per-play basis and scaled 0-100. According to ESPN Stats & Information, in Houston’s last two games, the team ranks last in that category, with 6.2 points out of 100. Mills’ Total QBR of 0.8 was the fourth-lowest in the last five seasons.

Part of the reason for the poor passing game is the way the Texans have struggled to run the ball, which is supposed to be a focal point of their offense. Culley said Wednesday that he isn’t considering abandoning the team’s running back-by-committee approach, and he feels that all three veteran backs -- Mark Ingram II, David Johnson and Phillip Lindsay -- “have different ways of being able to help” the team.

Since Week 1 when Ingram ran for 85 yards and a touchdown on 26 carries, the Texans’ running game has slowed down. Over the last two weeks, the Texans are averaging 2.6 yards per rush, which is the second-worst in the NFL in that time. Houston’s EPA (expected points added) in the last two weeks ranks 30th in the NFL over that span, ahead of only the Washington Football Team and the Denver Broncos.

“A lot of it is just they have to play with a tighter front seven, rotate a safety down, play with more man coverage, and it opens it up for the receivers to just win their matchups,” Mills said when asked how the pass game opens up once the run game is working. “The defense can’t really apply any help coverage where they’re double-teaming people and making it hard on the passing game. I think if you have complementary football in both the run game and pass game, it kind of balances it up where you can do both efficiently.”

The other thing Culley points to for Houston’s offensive struggles is the amount the team is “playing behind the sticks” because of a high number of offensive penalties in the last two games. Houston has been flagged for six offensive holding penalties in the last two weeks, which is the second-worst in the NFL.

“We’re not the kind of football team that can overcome those types of things,” Culley said.

Since the start of training camp, Culley has been preaching the importance of eliminating penalties to his team because due to the roster makeup, the team has little margin for error, especially on offense.

“The way we’re built is that if we play the game the right way, we eliminate the penalties. ... Penalties are happening during the plays where we’re getting positive yards and then getting backed up," he said. "Those are the things that we’ve got to get better at, and I think our run game will improve because of that.”

But despite the way Mills played on Sunday, Culley said the way Mills has reacted to his mistakes has him hopeful the Texans will see growth from the third-round pick, starting with Week 5 against the New England Patriots (1 p.m. ET on Sunday, CBS).

“Most rookies going through what he went through on Sunday, you would [be] really concerned, but I’m not concerned,” Culley said. “I see the same look in his eyes. He comes and prepares the same way. We’ve sat down, and we’ve talked one on one on what we need from you, what’s expected from you for us to move forward and for us to have a chance to get this offense to where it needs to be.”