There were questions about Houston's draft back in April. The knocks were that the team didn't address needs and reached for players when there were better options available. This preseason, each rookie the Texans drafted has shown some good things, and a few could make a significant impact. Here’s a look at how the top-three draft picks are performing:

Top pick: LB Whitney Mercilus (first round, No. 26 overall) -- Mercilus was drafted in the first round to rush the passer. He led the nation with 16 sacks in his final year at Illinois in 2011, which tied Simeon Rice’s single-season school record. There was some debate when he was drafted about how Mercilus would fit in with the Texans given the way Connor Barwin and Brooks Reed played last season. Still, a team can never have too many pass rushers. So far this preseason, he has four tackles and 1.5 sacks. All of his sacks came in the team’s first preseason game at Carolina. It looks like Mercilus will make an impact for the Texans this year. How much of an impact remains to be seen. Grade: B+

No. 2 pick: WR DeVier Posey (third round, No. 68 overall) -- Posey was an interesting pick given that he missed most of his senior year at Ohio State due to offfield issues. He has talent, but Kubiak knew it would take time for the rust to wear off. He has yet to catch a pass in the preseason and is behind Keshawn Martin and Lestar Jean in the No. 3 WR battle. Posey has shown flashes, but it might take time before he makes a significant contribution. “I just think that it has taken him a little bit more time to get going with the offense, so to speak,” Kubiak told reporters Sunday. “I mentioned many times throughout the course of the month, he did miss a year of football in a lot of ways last year, but his ability shows up.” Grade: C+

No. 3 pick: OG Brandon Brooks (third round, No. 76 overall) -- The first thing that stands out about Brooks is his size, but at 6-5, 340 pounds, he also has good feet. Brooks started 41 games in his college career at Miami (Ohio) and earned second team all-conference honors in three of his four years. Kubiak said he has seen good things from Brooks throughout camp, but he needs to be more consistent. Brooks has been competing with Antoine Caldwell at RG. Caldwell is winning the battle, and Kubiak said after Saturday’s game with San Francisco that he was disappointed with the second-string offense, which had some holding penalties. Brooks had one of those. He probably won’t start this year, but it seems like he has a bright future. Grade: B

The Texans may have found four steals in the fourth and fifth rounds of the draft. Martin was a fourth-round pick out of Michigan State who might end up winning the No. 3 WR spot. C Ben Jones (Georgia) has earned consistent praise from Kubiak. DE Jared Crick (Nebraska) will be in the two-deep, and K Randy Bullock (Texas A&M) is battling veteran Shayne Graham for the starting job.

Follow Texans blogger Sean Bielawski on Twitter, @CBSSportsNFLHOU.