The NFL said that in the first quarter of Saturday's game against Miami, Smith "forcibly removed the helmet of Dolphins guard Richie Incognito and then swung the helmet at Incognito in an attempt to strike him with it".
"Smith may attend team meetings prior to the next two preseason games but will not participate in practice or play in the Texans' games on Sunday, August 25 against the New Orleans Saints and Thursday, August 29 against the Dallas Cowboys," the NFL added.
"Beginning on Saturday, August 31, Smith is suspended for Week 1 of the regular season and may not take part in any team activities, including the club's game on Monday, September 9 against the San Diego Chargers."
Under the NFL's safety rules, a player "may not use a helmet that is no longer worn by anyone as a weapon to strike, swing at, or throw at an opponent".
However, Smith, 31, is entitled to appeal against the suspension within three business days and he told the Houston Chronicle he planned to do so, describing the penalty as "a little harsh".
"I didn't swing (the helmet) at him," Smith, a Pro Bowler in 2011, was quoted as saying. "I was restrained. I caught myself. I did it out of frustration, but I brought the helmet back slow to my body so I wouldn't hit him.
"I think the suspension is a little harsh because I restrained myself. I will appeal. Anybody would in this situation. I want to state my case. I've never had anything like this before. I'm surprised it included a regular-season game."
- Sports & Recreation
- American Football