Updated: 26 APR 21 12:46 ET

By Alex Rogers, CNN

(CNN) -- Former Rep. Doug Collins, a top ally of former President Donald Trump, announced Monday he will not run for office in 2022, taking out a potential top-tier candidate for a crucial Georgia race that could determine the future control of the Senate.

For months, Collins weighed a bid against Democratic Sen. Raphael Warnock, but Trump has signaled his support for football great Herschel Walker, effectively freezing the GOP primary field as Walker makes his decision.

"For those who may wonder, this is goodbye for now, but probably not forever. I do plan on staying involved in shaping our conservative message to help Republicans win back the House and the Senate and help more strong conservative candidates get elected here in Georgia," Collins said. "I believe that we, as conservatives, must be able to clearly communicate our values and I will help keep that fight going."

Collins, the former top Republican on the House Judiciary Committee, was a strong defender of Trump during his first impeachment trial and touted in his statement his work on the criminal justice overhaul bill known as the First Step Act.

But Collins had no appetite for a brutal primary fight like in 2020, when he ran against Republican Sen. Kelly Loeffler, after she was appointed rather than himself to the job by Gov. Brian Kemp. Loeffler beat Collins, and then lost to Warnock by two points. Collins also officially declined on Monday to run against Kemp, who drew Trump's ire for certifying his loss in the state against Joe Biden.

Florida GOP Sen. Rick Scott, the chairman of the National Republican Senatorial Committee, had discussed the last cycle with Collins, when the NRSC -- under a different staff and leadership -- torched Collins' campaign in order to secure the primary for the incumbent Loeffler. Scott assured Collins that the NRSC would not get involved in the open 2022 primary. In March, the Republican consulting firm OnMessage, which counts Scott among its top clients but is not affiliated with any Georgia Senate candidate, released a poll showing Collins in the strongest position in the GOP primary.

Collins' decision will again focus attention on Walker. Trump has known the former Georgia Bulldogs running back and Heisman Trophy winner since the mid-1980s, when he gave Walker a contract extension to play for his United States Football League's New Jersey Generals. The Walker and Trump families became close; Donald Trump Jr. recounts in his book "Triggered" that they went to Disney World when he was 6 and that Walker would visit the Trumps at their house in Greenwich, Connecticut. Walker later appeared on NBC's "The Celebrity Apprentice" with Trump and encouraged his 2016 and 2020 presidential bids.

In December, Walker tweeted a video supporting Trump's effort to overturn his loss and subvert the will of the electorate. Trump responded, "Herschel is speaking the truth!"

In March, Trump publicly pushed Walker to run for the crucial Senate seat. But last week, Walker didn't seem to be in any particular rush to announce.

"Right now, (I'm) just going through the process and thinking about it," Walker told CNN. "Not really talking a lot about it."

Some Republicans are privately nervous that Walker's indecision has put the brakes on the GOP effort to defeat Warnock, who is stocking up millions of dollars in anticipation for another bruising campaign. Walker, a Texas resident, is a political neophyte.

"I think there's a lot of anxiety, down here about, like, what his campaign will actually look like," said a Georgia Republican operative.

Besides Walker, other potential GOP Senate candidates include Loeffler and Reps. Drew Ferguson and Buddy Carter.