Alex Rodriguez, if he named fellow major league players for taking steroids, may have done so because he wanted to avoid appearing before Congress, including Sen. John McCain, a source who was close to A-Rod at the time told The Post.

“I 100 percent believe he got off the hook of testifying in Congress because he cooperated,” the source said, after reviewing the recent Espn Report.

The former Yankees third baseman revealed to federal agents in 2014 he had been told by Biogenesis founder Anthony Bosch that Manny Ramirez, Ryan Braun and one other All-Star player were also performance-enhancing drug clients, according to a blockbuster ESPN report released Wednesday.

The source who was close to A-Rod made clear he did not know whether A-Rod was meeting with the government at the time.

Instead, the source was opining now on A-Rod’s motivations, given the ESPN report.

Rodriguez gave the agents those names when he met with two assistant U.S. Department of Justice attorneys and seven Drug Enforcement Administration agents on Jan. 29, 2014, according to ESPN’s report.

Major League Baseball, just weeks before that 2014 meeting, suspended Rodriguez for one year for obstructing its investigation into steroid use and ties players had to Biogenesis founder Bosch.

The feds were focused on Bosch and that was perhaps Rodriguez’s best chance of becoming a cooperating witness, the source speculated.

The late Sen. McCain, over the previous 10 years, had held hearings on steroid use at which players, including Sammy Sosa and Mark McGwire, testified, and even introduced bills to standardize drug testing in sports.

The concern, the source speculated now, was he would call Rodriguez to testify and A-Rod would be caught in a web of lies.

“Lying to ESPN is one thing, but if the government was involved he knew he was going to prison,” the source said.

“A-Rod knew if he testified they were going to keep track of everything he said, and if it wasn’t all straight he would be indicted.”

There was certainly a hometown precedent.

Former Yankees hurler Roger Clemens testified before Congress in 2008 saying he had not taken steroids.

A Federal Grand Jury in 2010 indicted Clemens on six felony counts of perjury, false statements and obstruction of Congress.

Ultimately, Clemens was cleared of the charges.

“Absolutely, I think he was scared,” the source said.

Rodriguez, the source said, got his drugs from his cousin Yuri Sucart Sr. and did not know what was in them.

Their joke was he was getting B-12 vitamins, the source said.

“B-12 was wink-wink.”

The ESPN report said Rodriguez told the agents Sucart blackmailed him when their relationship soured, threatening to tell the media about his steroid use.

Rodriguez declined comment.