The 90-member Haryana Assembly will go to the polls on October 21 and the results will be declared on October 24.
Nandal had twice contested the Assembly elections against Hooda from the Garhi Sampla-Kiloi constituency in Rohtak district on INLD ticket in 2009 and 2014. He finished Hooda's nearest rival on both occasions.
This time, Hooda is most likely to re-contest from his home turf.
The BJP's vote share in the Garhi Sampla-Kiloi segment in the last Lok Sabha polls rose substantially compared to the previous elections.
Hooda's son Deepender Singh Hooda, who was the three-time MP from Rohtak, faced a humiliating defeat in the last Lok Sabha polls.
"This time, Bhupinder Singh Hooda is fighting on two fronts to re-establish himself and to ensure the Congress' return to power in the state, as he forced the party high command to name him as the Congress legislative party leader just ahead of the Assembly polls despite all odds," a political observer told .
Hooda is facing cases filed by the Central Bureau of Investigation (CBI) and the Enforcement Directorate (ED) for granting approval to a land deal of Rahul Gandhi's brother-in-law Robert Vadra in the fag-end of his second stint as the Chief Minister.
"The delay in declaring Hooda as the party's de facto chief ministerial face is a blessing in disguise for Hooda. If he was declared as the party leader well in advance, the BJP government in the Centre might have tightened the noose around his neck by using the probe agencies," a senior Congress leader said.
"At least, till the election process gets over, they can't use the investigating agencies against him," he added.
In the 2014 Assembly polls, the BJP improved its 2009 tally of four to 47, followed by the INLD with 19 legislators and the Congress with 15 seats.
Two seats went to the Haryana Janhit Congress (HJC), and one each to the Shiromani Akali Dal (SAD) and the Bahujan Samaj Party (BSP). Five Independent candidates were also elected.
( With inputs from IANS )