Clint Eastwood once took care of business in the movies as tough San Francisco cop Harry Callahan. Now, the Vikings have an enforcer in the secondary.

Safety Harrison Smith might be Minnesota’s best defensive player. And his teammates have a nickname for him.

“We call him ‘Dirty Harry,’ ” cornerback Captain Munnerlyn said. “He comes in and cleans up the dirty work for us and makes plays.”

The nickname comes from the five “Dirty Harry” movies Eastwood starred in during the 1970s and ’80s. Smith doesn’t mind hearing it.

“A lot of people have called me that since I’ve been around here,” said the third-year man. “I don’t know who specifically started that one. (Munnerlyn is) a fan of it. (Teammates) just think that I play hard, so it just kind of fit.”

The good news for the Vikings is Smith is likely to get his uniform dirty Sunday against Detroit. After not practicing early this week because of a sprained left ankle, Smith went through a limited workout Thursday and said he’s “pretty optimistic” about facing the Lions at TCF Bank Stadium.

“Just trying to get my foot (some work) and see how it feels,” he said. “It went pretty well. … I practiced like normal, just not as many reps.”

Smith was injured Oct. 2 when he took a hit in the first quarter of a 42-10 loss at Green Bay. Last Friday, he was wearing a boot and walking with the help of crutches.

“It really has improved every day,” Smith said. “So that’s all I can ask for.”

Linebacker Chad Greenway, who has missed the past two games because of a broken hand and broken ribs, sat out practice again Thursday. Vikings coach Mike Zimmer said Greenway will be examined Friday, when it will be determined whether there’s a chance he can play against Detroit.

As for Smith, Zimmer also was optimistic after Thursday’s workout.

“He’s healed pretty quick,” the coach said. “It’s been good. And he’s tough. He’s a tough guy.”

That’s one of the reasons for Smith’s nickname. Smith said he has had other nicknames, such as “Hit Man,” but that “Dirty Harry” might be his favorite.

“That one’s pretty good,” he said.

Follow Chris Tomasson at twitter.com/christomasson.