Rodriguez, who is fourth on the all-time saves list with 437, lost the Tigers' closer job last month when he was replaced by Justin Wilson. Rodriguez, 35, had an ERA of 8.49, four blown saves and a 1-4 record at the time of his demotion.
Until recently, he was used sporadically in mop-up duty, a role that he made clear on Tuesday he's not content filling.
"They have to test me? They have to find out if I can pitch? That's exactly what it means. I've never been in a mop-up situation. I haven't pitched the last 15 years, being consistent, putting up numbers being mop-up. That's not how I've made my living," he told The Detroit News before Tuesday's game against the Arizona Diamondbacks.
"But I guess I've got to be ready when I'm told and that's it."
When he made the closer switch, manager Brad Ausmus told reporters that "the goal is for Frankie to get right and get back to the way he pitched for us last season."
Rodriguez had 44 saves for the Tigers last season, his first with Detroit. He has seven saves this season.
Rodriguez said no one from the team has talked to him about their plans for him.
"To be honest, no one talked to me. No one tells me anything. They never ask my opinion. They never ask me if I am ready to do that or not. It was their decision. Nobody asks me anything," he told the News.
"Ask [pitching coach Rich] Dubee how many times he's talked to me. They are the ones who have all the answers."
Rodriguez has made five scoreless appearances since June 6, including the seventh inning in Tuesday's 7-6 loss. After David Peralta led off with a double against Tigers pitcher Chad Bell, Rodriguez entered in a 6-6 game. He struck out Paul Goldschmidt swinging, forced a groundout from Jake Lamb and got Chris Owings to fly out to center.
"I want to continue to get him into higher-leverage situations," Ausmus said after the game. "We're a lot better team when he's pitching in those situations successfully."
However, from May 19 until June 6, Rodriguez made only three appearances. He said his lack of opportunities has been frustrating.
"How is it going to be better if I don't pitch? They say one thing, but their actions say something else," he told the News. "How am I supposed to take that if I don't get into the game when the game is close or we have the lead?
"How am I supposed to take that?"
The Associated Press contributed to this report.