McLaren is trying to convince Fernando Alonso to make a surprise return, as it hesitates over a new contract for Sergio Perez.
Despite Perez closing on 2014 deal, McLaren is not yet sufficiently convinced about the Mexican's performance.
The team has singled out Alonso as an ambitious target as it tries to line up potential alternatives.
McLaren team principal Martin Whitmarsh said: "We are interested, but we have to be respectful of what is going on at Ferrari. Let's see how it pans out."
A DREAM OR REALITY?
An Alonso return to McLaren is nigh-on impossible for next season, with Alonso under contract at Ferrari and insisting that is his priority.
McLaren insiders have also suggested that they are not expecting any movement for 2014, and that the Alonso talks are more a dream proposition than a realistic option.
However, McLaren's stance leaves the door open for the start of its new Honda alliance in 2015.
Such a scenario could become more real if Ferrari's recent ramp up of infrastructure and personnel does not deliver the desired 2014 progress and Alonso loses faith.
Furthermore, the Honda partnership - with its commercial benefits - could give McLaren the financial firepower it needs to sway Alonso.
"Honda is a game change for us in all sorts of different ways," Whitmarsh admitted.
"It will be extremely positive for our fiscal horsepower and our ability to go out there and see if we can get the best assets that are available."
Perez said ahead of the Singapore Grand Prix that his deal was done for next season, barring a few final details.
However, McLaren says that matters are not quite as close as that - and Whitmarsh has made it clear that he still wants to see better form from the Mexican.
"Sergio has a tremendous benchmark in Jenson, who is consistent, a great quality driver, a great team player and who brings a tremendous amount of benefits to our team," said Whitmarsh.
"For a young charger like Sergio, he knows and I know that he has to come in and beat him. He hasn't done that consistently enough so far this year.
"He is going to give it a good go this weekend I expect."
IS ALONSO/RAIKKONEN LINE-UP SUSTAINABLE?
Amid the friction between Alonso and Ferrari that erupted at the Hungarian Grand Prix, McLaren felt it was worth sounding out the Spaniard's representatives about a future deal.
And although Whitmarsh has denied any direct talks with Alonso, he drew short of dismissing suggestions that their representatives have met.
Whitmarsh admitted that scepticism over the Alonso/Kimi Raikkonen pairing's long-term viability fuelled its hopes.
"I think a lot of observers do not believe that the driver line-up that Ferrari has, as strong as it is on paper, is potentially going to be sustainable - and that is why people are speculating," he said. "You know that as well as I do."
VANDOORNE AND MAGNUSSEN IN THE FRAME
The other possibility is for McLaren to take a gamble and promote one of its young drivers - Kevin Magnussen or Stoffel Vandoorne - to race alongside Button.
The return of in-season testing means taking a rookie for 2014 is not as difficult as it has been in recent years.
"They are in the frame," admitted Whitmarsh. "We are very fortunate at the moment that we have some fantastic young talent coming through and they deserve to be in F1.
"We have in Kevin and Stoffel two of the hottest talents not in F1, and certainly it is our ambition to get them into F1."
In reality, McLaren will most likely commit to a single-year deal with Perez for 2014 and then resume efforts to lure Alonso for 2015.
"In all probability, our driver line-up will remain unchanged next year - let's be honest about it," said Whitmarsh. "But you never know. We will see.
"I think at the moment our two guys have worked hard and well through a difficult season, they deserve another go and we will see what happens."
2007 ROW NO IMPEDIMENT
McLaren's interest in Alonso is not a surprise in terms of the Spaniard's talent, because he is widely regarded as one of the very best on the grid.
Whitmarsh admitted he was slightly baffled that his Singapore admission that McLaren would welcome Alonso actually caused such a stir.
From the archive: why McLaren/Alonso didn't work out
"I was asked a question and I answered it," he said. "Would you like Fernando Alonso in the team? Yes. Would you consider him in the team? Yes. But that isn't in my choosing.
"What else do you say when you are in my shoes? You don't say, 'well I don't' want to comment on that' - because you are only stating the obvious. That is why I don't think it is such a revelation."
What is of significance, however, is that McLaren is openly contemplating taking Alonso back after a fractious parting of ways at the end of 2007.
When asked if the strained relations from that season meant it impossible Alonso could return, Whitmarsh said: "Not in my name. That was 2007 and I was there.
"It was, to be honest, fairly acrimonious at the end. A lot of passions were raised. We are in a different circumstance now.
"From my perspective there is no impediment but whether or not there is from Fernando... I would hope not but I would doubt it.
"We are perfectly cordial when we talk. He wants to win, he wants an environment around him that is based on winning but we will see what happens with his current team."