Although the Woking-based outfit ended 2013 without a podium finish for the first time since 1980, Whitmarsh is excited about the prospects for next season with the grid needing to adapt to changes in regulations.
He told Autosport: "It has been a long season and it seemed longer than I have ever known a season. Now I am excited about the future and that is a nice thing.
"With the big rule change coming for 2014, it really is a clean sheet here. There are no excuses for next year."
McLaren finished fifth in the constructors' championship, 474 points behind winners Red Bull.