Joe Biden has a long list of calls to make – and to field – today. But one of the most important conversations he will potentially have is with Senate Majority Leader Mitch McConnell

The two men have not spoken yet – a Biden aide said that would be premature, a McConnell adviser said it hasn’t happened – but they expect that call to be made later today.

And look for Biden to reach out to McConnell, who will likely play a key role in approving members of Biden's possible cabinet if Republicans continue to hold their majority, which even Democrats concede is likely.

For all the talk about when Biden and President Trump will speak – Biden will not initiate that call, an aide says – he will reach out to McConnell when the time is right to begin those conversations.

Biden and McConnell have a long relationship, serving together in the Senate for decades, but also working closely and cutting deals during the Obama administration.

“He will need that relationship more than ever now,” a friend of Biden’s said.

For McConnell’s part, he intends to take a remarkably cautious approach to Biden – given the sensitivity surrounding President Trump’s expected refusal to concede – but a person close to him said he will speak to Biden when the time is right and will be eager to do so.