Two weeks remain in the ATP regular season, the first of which features two 500 tournaments in Basel and Valencia.  Even after Rafael Nadal withdrew from the former event, half of the top 10 remain in the draw there.  Although less studded with stars, the Valencia field has attracted several men who have shone at the Masters 1000 tournament in Paris that follows. 

Basel:

Top half:  Defending champion Juan Martin Del Potro thrust his US Open disappointment behind him with an outstanding campaign in Asia.  Just a tiebreak short of his first Masters 1000 title in Shanghai, Del Potro now aims to win a second straight 500 tournament.  Few are his early obstacles en route to repeating a triumph in Tokyo.  Three qualifiers and a wildcard populate his quarter, although second-round opponent Marcos Baghdatis always has proved a thorn in his side.  Moscow champion Richard Gasquet could await in the quarterfinals, a pivotal match in his attempt to qualify for the World Tour Finals.  Del Potro has less at stake in Basel than Gasquet does, but his superior serve and first-strike power has allowed him to dominate this matchup. 

Rarely has the Argentine faced fourth seed Stanislas Wawrinka, whose breakthrough season culminated with a US Open semifinal.  Not always at his best on fast indoor courts, Wawrinka might need to fend off an upset bid from Daniel Brands.  Seventh seed Andreas Seppi, who shares the Swiss player’s preference for slow courts, should pose less stern a barrier to a semifinal clash with Del Potro.

Bottom half:  A towering test looms ahead of second seed Tomas Berdych, often vulnerable in the early rounds.  Berdych is the only top-10 player on either Tour who has not won a title this year, and the massive serve of Ivo Karlovic could fluster him.  So could the raw but fearless Vasek Pospisil, who upset the Czech at the Rogers Cup this summer.  Berdych also has lost all three of his hard-court matches against quarterfinal opponent Kei Nishikori, one of those defeats coming at Basel in 2011.  A finalist there that year, Nishikori struggled with a back injury at his last tournament in Shanghai. 

Home hero Roger Federer could empathize with that situation, having suffered chronic back woes for much of 2013.  Embedded in the middle of the bottom half as the third seed, Federer opened his campaign smoothly with a victory over Adrian Mannarino.  Ahead for him lies a first meeting with the man who modeled much of his game on the Swiss star, Grigor Dimitrov.  “Baby Fed” has struggled to string together strong results, so a letdown after his first career title in Stockholm might cost him against quirky opponents Radek Stepanek and Alexandr Dolgopolov.

Valencia:

Top half:  A return to home soil should invigorate world No. 3 David Ferrer, the only top-10 man to attend Valencia.  The draw gods did not smile on the title favorite, positioning him opposite Gael Monfils in the first round.  Monfils upset Federer and challenged Novak Djokovic in Shanghai, and he won his only meeting with Ferrer on indoor hard courts three years ago.  Should the Spaniard survive the upset, he could set up a rematch of last year’s final at the Paris Masters 1000 tournament against Jerzy Janowicz.  On the verge of defending those valuable points next week, both men will feel eager to build momentum.  Janowicz’s own early test looks against Joao Sousa, a titlist earlier this fall in Kuala Lumpur after upsetting none other than Ferrer. 

Spaniards dominate the list of potential semifinal opponents for the Paris finalists, most notably Nicolas Almagro.  The third seed recorded one of his better 2013 results with a quarterfinal appearance in Shanghai, and he often raises his game a notch on home soil.  A battle of compatriots and flamboyant shot-makers would pit Almagro  against wildcard Fernando Verdasco in the second round, with the enigma of Fabio Fognini destined for the survivor.  Fognini delivered one of his characteristically mercurial efforts on Monday by drifting into a third set and then dishing out a bagel there.  Of all these Mediterranean men, Verdasco likely wields the weapons best designed to unsettle Ferrer or Janowicz.

Bottom half:  The first upset already rippled through the Valencia draw when local wildcard Roberto Bautista Agut came from behind to knock off Kevin Anderson.  Several other early matches scintillate almost as much as Ferrer-Monfils.  Among them is the slugfest between fourth seed John Isner and Ernests Gulbis, enjoying the best season of his career.  Isner becomes a much less formidable opponent away from American soil, and Gulbis has won both of their previous meetings. 

Still a bundle of squandered talent, Bernard Tomic has not won more than one match at any hard-court tournament since February, appearing to go through the motions last week in a Stockholm loss to Jack Sock.  Nevertheless, he catches inspiration at unpredictable moments, which could create intrigue against US Open quarterfinalist Mikhail Youzhny.  After that showcase of two smooth, aesthetically pleasing styles, the youngster or the veteran will meet the winner of an  all-German clash between second seed Tommy Haas and Philipp Kohlschreiber.  While the former won the Vienna title last week, the latter lost in the first round there.  But one wonders how  much energy the 35-year-old Haas has kept in reserve after the arduous three-setters that he played last week.  He will need all of what remains to master Gilles Simon, who also has won an indoor title this year.  Toppled by compatriot Benoit Paire in the first round of Shanghai, Simon will pursue revenge in the second round on the slower court of Valencia.