Serna has proved herself a tough competitor since making her tour debut in 1996 without ever threatening to become a top-10 player.
World ranking: 19
Australian Open best:
3rd round (2002 & 1997)
2003: 2nd round
2002: 3rd round
2001: 2nd round
The Spaniard secured her place among the leading women with a superb run of form in early 2003 but was unable to build on a good start to the year.
A remarkable 14 straight wins during April brought Serna titles in Estoril and Budapest, as well as helping Spain defeat Australia in the Fed Cup.
But a solitary Grand Slam quarter-final appearance, at Wimbledon in 2000, shows what Serna has to do if she is to step up to the next level.
Reaching the last 16 at the French Open was a start and losing to fifth seed Amelie Mauresmo no disgrace, but second-round exits at the Australian Open, Wimbledon and the US Open were disappointing.
Chanda Rubin and Maria Sharapova were the biggest scalps she claimed in 2003 and the Spaniard has only beaten Justine Henin-Hardenne among the world's top five players.
She has a 2-0 record against the Belgian but has not met the world number one since 2001.
Serna will need to improve to get past the third round in Melbourne for the first time.