Against top-10 opponents this year, Murray has won 11 and lost eight of his 19 contests.
Speaking to ATPWorldTour.com, the Scot said: "Obviously this year [Novak's] level has been incredible. Since the beginning of last year, my results against him and Roger, from my perspective, haven't been good enough. I need to do better in those matchups.
"It's harder playing against the best players. Those two are two of the greatest players of all time, so there is no disgrace in losing to them. But I do feel like I need to start doing better in those matchups, because the scoreline in the last couple of matches there hasn't been good."
Murray will be seeded second at the upcoming ATP World Tour Finals at the O2 Arena in London before he attempts to win the Davis Cup for Great Britain against Belgium later this month.