Carlos Rodriguez summarizes his evaluation of Li Na's performance in 2013 in one word.

Proud.

The rating is not only for the Chinese tennis star's most consistent year. It works fine for the roller-coaster WTA Championships final in Istanbul on Sunday night, in which Li blew a one-set lead and fell to reigning champion Serena Williams 2-6, 6-3, 6-0 .

"It was very close. I have to say I am proud of what she did today… She showed me that she can do what I ask her to do," said the well-known tennis coach.

Li, who just clinched her career-best world No 3 coming into the night, challenged Williams from the very start with a barrage of flaring plays - including some fantastic volleys and penetrating backhands, and stormed to a 6-2 win after breaking the American twice.

But Williams somehow found her best form again and took over the match from a 3-3 tie in the second set and reeled off the next games to extinguish an exhausted Li's hope of lifting her second title in the season.

"What is important is, I've seen where Li Na's improved there, thanks to Serena, who pushed her (to a higher level). I am happy that Li found some very good things," Rodriguez said.

"She (Li Na) played a level of tennis she wasn't used to playing. I don't know if she understands how hard it is for her to do what she did today to go to the net against Serena. To have the courage to always make some volleys and win some points, it is not easy…I think now physically and technically Li is a much better player than before."

The Argentine coach also thinks Li Na has grown a lot by opening up to people more.

"It is important for her to try to share emotions with Dennis, her husband, with Alex (Stober, Li Na's fitness coach) and with me. And my job is to try to explain to her that if she is not going to show her emotions, it will be very difficult for her in the future to become a better player and a better person."

Communication did work for Li. When she was under enormous stress from some bad results and naysayers and pondering a possible retirement after Wimbledon this year, she resorted to her coach, who talked her out of it.

"I told her if she wants to stop something, she can do it, as long as it is for good reasons. (But) if you stop playing tennis because you don't like to lose and you can't handle (the pressure) then it is a bad reason. You must have courage to accept your responsibility to be a champion. A champion loses and wins, and tennis is about that - losing and winning."