Emmanuel Acho, an author and former National Football League player, will host a post-finale special of “The Bachelor” after the show’s longtime host, Chris Harrison, said he was “stepping aside” after he made comments that were dismissive of racism.

Mr. Acho, who wrote the book “Uncomfortable Conversations With a Black Man” and hosts a show by the same name, said in a statement that it was “both an honor and privilege” to host the hourlong special on March 15.

“This is an incredibly pivotal episode on one of the most storied shows in television history,” he said.

The installment of a Black host caps a season that featured the ABC franchise’s first Black “Bachelor,” Matt James, but has also been overshadowed by a series of controversies amid calls from the show’s fans to increase its efforts toward diversity and inclusion.

Mr. Harrison’s hiatus came after an interview with Rachel L. Lindsay, the show’s first Black “Bachelorette,” in which Mr. Harrison defended racist actions by one of this season’s three finalists.

The “After the Final Rose” special will “cover the current events about the franchise,” ABC said in a statement, as well as conversations between Mr. Acho, Mr. James and the three finalists.

One of the finalists, Rachael Kirkconnell, has faced criticism over photos that have recently surfaced, including one of her attending an “Old South” plantation-themed ball. Ms. Kirkconnell apologized in an Instagram post, saying, “I was ignorant, but my ignorance was racist.”

Mr. James said that the interview between Mr. Harrison and Ms. Lindsay “was troubling and painful to watch,” adding that “it was a clear reflection of a much larger issue that ‘The Bachelor’ franchise has fallen short on addressing adequately for years.”

Mr. Harrison, who is still listed as the show’s host on its website, apologized, writing on Instagram that his comments, like his use of the term “woke police” in defending Ms. Kirkconnell, were “unacceptable.”

Ms. Lindsay had suggested last week that Mr. Acho “would be fantastic” as a host for the special because he has been “very outspoken about racial injustice, for social justice, and has pretty much been the person who said, ‘I can have these uncomfortable conversations and people trust it.’”

Mr. Acho said on Instagram about the announcement: “I love being a bridge for reconciliation. Our world is disconnected & divided, my goal is to unify.”

Mr. Acho, an analyst for Fox Sports, is a former linebacker for the Cleveland Browns and Philadelphia Eagles football teams. He left the N.F.L. in 2016 to join ESPN as an analyst.

His YouTube show, “Uncomfortable Conversations With a Black Man,” has covered topics like policing, national anthem protests and “Karens & Cancel Culture.” An episode titled “A Conversation With the Police” has more than two million views.