Neil Patrick Harris pays tribute to late costar who taught him ‘countless lessons'

Neil Patrick Harris is paying homage to his on-screen dad James B. Sikking.

Emmy-nominated actor Sikking played Neil’s dad on Doogie Howser, MD, and left the best of impressions on the How I Met Your Mother star.

Remembering Sikking, who died of complications related to dementia at the age of 90 on July 13, Neil wrote, “Jim Sikking played my dad in Doogie Howser, M.D., and was one of the kindest, wisest, funniest, and most generous people I’ve ever known.”

He continued: “A true professional. He treated everyone with respect, taught me countless lessons, yet always had a spark of mischief in his eyes. It was an absolute honor to be his son. My condolences to his actual family for their loss. #RIP”

Doogie Howser, M.D. ran from 1989 to 1993 after Sikking had already won an Emmy nomination for playing S.W.A.T. leader Lt. Howard Hunter on Hill Street Blues from 1981 to 1987.

He played Captain Styles in 1984’s Star Trek III: The Search for Spock, starring alongside icon Leonard Nimoy. He played the role of FBI director Denton Boyles in Alan J. Pakula’s 1993 legal thriller The Pelican Brief.