The Spain international has rediscovered his best form under new manager Antonio Conte in the 2016-17 season following a disappointing second season in England.
Costa has scored 17 goals and has made five assists in 30 appearances in the Premier League in the current campaign.
Kane, on the other hand, has found the back of the net in 20 times in a mere 23 top-flight appearances to help Spurs to challenge the Premier League leaders.
The England international has scored 72 goals in 96 Premier League games over the past three seasons to establish himself as one of Europe’s top strikers.
Writing in his Daily Mail column, former Arsenal defender Keown believes Costa is still a better player than Kane despite the Englishman’s impressive goal record.
“I would also select Diego Costa over Harry Kane. At the moment, Costa is the better player — though Kane is not far away,” Keown said.
“In a one v one Costa has caused defenders so many problems this season. He was desperately unlucky to miss out on the Player of the Year shortlist.”
Chelsea will take on Tottenham in the FA Cup semi-final at Wembley on Saturday evening.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news