The race could tilt or possibly even lean to Perdue if one or both of the below events occur:
a.) Warnock becomes unpopular / is too liberal for Georgia voters / makes a gaffe, possibly relating to Israel / Palestine, that alienates some supporters.
b.) The 2022 midterms are good for the GOP.
Assuming neither of the above occur, then the race is tossup or tilt Democratic. While Warnock may be the incumbent, remember, he won in 2020 because of a surge in turnout in Atlanta and the gravity of the race. If 2022 is a decent year for Democrats and the race progresses to a runoff, it's possible turnout is down from 2021 since the race matters less and Perdue wins. If, conversely, 2022/2023 is a repeat of 2020/2021, with it being a 50-50 tie and the Senate balance hinging on the Georgia race, then perhaps Warnock, since Perdue is a somewhat weakish candidate, given that he underperformed Trump in 2020 by 1% in a year where Trump did historically bad for a Republican presidential candidate in Georgia.
Didn't Perdue already take himself out of the running for this seat?