John Isner beat Nicolas Almagro in the Houston final last year -- his first clay-court title. (Mike Ehrmann/Getty Images)
The Watch List spotlights the must-know storylines for the upcoming week in tennis. After the non-stop hard court grind over the last six weeks through the Middle East, Indian Wells, Miami and Davis Cup, this week offers a slight breather before the European clay court season begins in earnest. With most of the top players taking a break this week, there's nothing but opportunity at the four tournaments.
U.S. Men's Clay Court Championships
John Isner, who now sits at a career-best No. 9, will try and defend his title in Houston as the top seed in a field that includes an array of Spanish clay court specialists, including Tommy Robredo, Nicolas Almagro and Fernando Verdasco. Last year's win was Isner's first clay court title.
The early rounds should offer some interesting matches. Jack Sock opens against eighth-seed Ivo Karlovic, and Isner could open against the flashy and athletic Dustin Brown in the second round. Sam Querrey is also in the draw and could play Lleyton Hewitt in the second round.
Copa Claro Colsanitas
Ask Jelena Jankovic about her return to the top 10, and she points to her title here in Bogota last year, when she made a run through a relatively easy draw (not that she made it easy on herself) to get back to her winning ways. Now ranked No. 9, Jankovic returns as the top seed to defend her title at the international-level tournament, with Sloane Stephens joining her as the No. 2 seed. The rest of the field is made up of players ranked outside the top 50, so this is a great opportunity for Stephens to, at a minimum, make her first WTA final. A potential semifinal against another young player, Caroline Garcia, would be fun to see.
If you're not ready to let the spring hard-court season go, you can get another glimpse here. No. 3 Agnieszka Radwanska is playing her home tourney in Poland for the first time (a rule prohibiting top players from "playing down" to lower-level tournaments prevented her participation last year). Radwanska tops a field that includes Roberta Vinci, Carla Suarez Navarro and Alize Cornet. Also in the draw via special entry is Monterrey finalist Jovana Jaksic, who will try to keep up her momentum and replicate her success in Monterrey to break into the top 100.