(CNN) -- An eagerly-anticipated clash between two of the greatest boxers of the modern era looks likely to happen this year if the two camps can compromise on a date.
U.S. boxer Floyd Mayweather Jnr took to his Twitter account this week to throw down the gauntlet to Manny Pacquiao, calling on his arch-rival from the Philippines to "step up punk" for a May 5 fight.
But Pacquiao's official website said that the 33-year-old wanted a date at the end of that month.
And Filipino broadcaster ABS-CBN reported that Pacquiao's adviser Michael Koncz said late May was preferable so that a temporary outdoor stadium could be constructed in Las Vegas to maximize revenue from the showdown.
However, Pacquiao's business manager Eric Pineda told CNN that the fight might not take place until November.
"It's not going to be in May," Pineda said on Thursday. "As far we know, he (Mayweather) has a jail term to serve. With a November date, he can still do a lot of training in jail."
Mayweather was sentenced to a 90-day prison term after being found of domestic violence, however a judge in Nevada ruled last week that the Mayweather could postpone reporting to jail until June because he had already lined up a fight date in May.
Mayweather chose Twitter to issue his challenge to Pacquiao.
"Manny Pacquiao I'm calling you out let's fight May 5th and give the world what they want to see," he wrote on Tuesday. "My jail sentence was pushed back because the date was locked in. Step up punk."
The two fighters have had a famously rancorous relationship.
Last year, Pacquiao filed a lawsuit in a federal court in Las Vegas for defamation against Mayweather and others for allegedly claiming he had used performance-enhancing drugs.
Pacquiao had been infuriated by the insistence of Mayweather and his team at Golden Boy Promotions that both fighters submit to Olympic-style blood testing in the buildup to a previous "super fight."
The talks between the two parties broke down. "Floyd Mayweather is a coward. He will never fight anyone that will remotely give him a tough fight," Pacquiao's promoter Bob Arum said at the time.
The 34-year-old American boxer has won all 42 of his professional fights (26 by knockout) but Pacquiao, 33, also has an impressive record with, with 54 wins from 59 bouts -- 38 by knockout -- plus three losses and two draws.
He is the first boxer in the sport's history to have won world titles in eight weight divisions and recently launched a successful political career after being elected to the Philippine House of Representatives in June 2010.
Pineda said the details of the much-vaunted fight between Mayweather and Pacquiao were still being studied.
"We haven't seen a contract yet. It's all still on the drawing board," he said.