DENVER -- A controversial billboard near Invesco field asks football great Ricky Williams, who was kicked out of the league for smoking pot, to come play for the Broncos.

The billboard at 18th Avenue and Federal Boulevard reads: "Ricky, come to Denver where the people of Denver support your SAFER choice."

Williams was kicked out of the NFL after testing positive for marijuana four times.

The Miami Dolphins still hold the rights to his contract and haven’t said what they plan to do with them.

Tuesday, Williams said he wanted to return to football, and the group Safer Alternative For Enjoyable Recreation (SAFER) put up the billboard saying he would be welcome in Denver.

SAFER believes alcohol is more dangerous to society than marijuana.

Mason Tvert, the group's executive director, said Williams has been "demonized and punished because he chooses to use marijuana instead of alcohol."

SAFER is pushing a November ballot issue that would tell Denver police to make marijuana enforcement a low priority crime.

Denver voters have already voted to decriminalize the possession of less than one ounce of marijuana. Users can still be prosecuted under Colorado state law.

The billboard brought a mixed reaction from people who saw it on Wednesday.

Byron Whissler told 7NEWS if Williams wants to play in the NFL, he has to follow the rules.

"You have to pay the penalty for it," Whissler said.

Larry Day said pot should be legalized. He said alcohol has caused more problems for society than marijuana.