Re-signing Fernando Alonso would be a "no-brainer" for Renault, but McLaren chief executive Zak Brown wonders whether he has the appetite.
Renault will lose Daniel Ricciardo to McLaren at the end of the 2020 Formula 1® season but Alonso and Sebastian Vettel are high-profile candidates to replace him.
Alonso, a two-time F1® world champion with the French outfit, walked away from the series in 2018 following four tough years with McLaren and has gone on to win the 24 Hours of Le Mans and participate in the Dakar Rally, while a third attempt at the Indy 500 is planned for this year.
The Spaniard's manager Flavio Briatore this week claimed the 38-year-old is ready to return to F1® and Brown thinks it makes sense for Renault to make an approach.
However, he is unsure Alonso would be willing to drive for a team that is not challenging for victories.
Brown told Sky Sports: "I spoke with him the other day, I was kinda poking around, and I think he's undecided.
"If I was running Renault that's who I'd put in the car; a big name, fast as anyone, won two championships with them so he's got history.
"So from a Renault perspective I think he's a no-brainer to put in, but whether Fernando wants to get back to 22 races with a car that doesn't look like it's capable of winning yet.
"With Fernando's stature what would get him to jump in a seat is if he thinks he can be on the top of the podium.
"Given they're on a similar journey back to the front [to McLaren] - and I think they'll get there, they're a great team, great resources, great company whose been there done that before - I don't know if Fernando has the appetite to be on a three-year journey rather than getting in a car that he can win in in '21."
Mercedes boss Toto Wolff said a move for Vettel would be "a good marketing story" for the Silver Arrows, who look like the four-time champion's only other option to Renault.
News of the German's decision to leave Ferrari after the 2020 campaign came too late for McLaren to make a move and Brown hopes it does not leave him without a seat next season.
"We were already far down the path with Daniel, we knew it was either going to be Daniel or Carlos in our car. We knew that in the winter. By the time this all popped up with Seb, our ship had sailed," said Brown.
"I like where Daniel's at in his career, he's got something to prove, he's hungry. Seb's an awesome champion. I don't know what will happen with him, kinda like Fernando because if he wants to get in a car where he can go and win the championship right away it doesn't appear those seats are available, so does he want to hit the reset button and get on a three-year journey somewhere or is he done?
"I think he clearly still wants to race so it would be unfortunate if you had a four-time world champion who wants to race but can't find that seat that he deserves."