After just a year with McLaren, Perez suddenly finds himself looking for another seat as Whitmarsh has opted to promote development driver Kevin Magnussen to partner Jenson Button for 2014.
Whitmarsh has refused to find fault with Perez, instead insisting it was the right time to hand Magnussen his opportunity after clinching the World Series by Renault 3.5 championship.
But that has resulted in Whitmarsh speaking with Lotus team principal Eric Boullier and Force India's Vijay Mallya about the possibility of them taking on Perez.
"I am trying to help him get a drive," said Whitmarsh, speaking to Press Association Sport.
"People say our decision was terribly late, but what I have said to him is to stand back from it a bit.
"I've told him the Ferrari seats have gone, the same with Mercedes, Red Bull and Toro Rosso, and in truth he wasn't in the frame for any of those so he hasn't lost a seat.
"At the time (of the decision) Williams had a seat, but that has now gone, but there is a Lotus seat, and one at Sauber, Force India, Caterham and Marussia.
"So there is no seat closed to him and we can have no accusations we made the decision too late.
"So I have rung Force India and I have rung Lotus. They both do a good job and I have recommended him because he deserves to be in Formula One.
"He is an exciting driver, and I don't want to talk about why we didn't re-sign him.
"I would rather say we saw such great potential in Kevin that we decided to sign Kevin.
"It was not about what Checo did wrong. What Checo did wrong was that Kevin existed. Kevin was part of our programme.
"If you go up and down the pit lane and speak to the knowledgeable people they will say Kevin is the most exciting young driver not in F1.
"Now I went up and down the pit lane (to speak to people about a deal for Magnussen) and no one wanted to do it, so we went for it."
Whitmarsh concedes there are those who may not understood how he can recommend Perez when he has just given the 23-year-old the boot.
But he added: "What I can say is that I had Kevin.
"We could have taken a lot of the drivers that are available, the experienced guys, but we made a decision we wouldn't take any of those guys in preference to Checo.
"That is why I can reasonably recommend him to another team because, as I say, he certainly deserves to be in F1. He is an exciting driver to watch, he will go for it and I enjoy watching him.
"When he was at Sauber I thought 'That was good, let's see what we can make of it', but it hasn't worked out for us.
"I don't regret it, I didn't have a Kevin last year - so it is as simple as that.
"If I didn't have a Kevin or a Stoffel (Vandoorne) now we probably wouldn't be making the change, but we have a Kevin, and we need to try to get him in."