Over the last several months, Usain Bolt and Yohan Blake have spent dozens of hours practicing at the same time on the same track under the watchful eye of the same coach.

When it comes to racing -- really racing -- the Jamaican sprinters have been crisscrossing the globe avoiding each other.

The head-to-head clash can't be put off any longer.

Bolt, the world-record holder, and Blake, the reigning world champion, will square off this week at the meet called, simply, the Jamaican National Senior Championships -- or, what most other countries would call the Olympic trials.

Heats in the 100 meters start Thursday, with the final for that event set for Friday night at National Stadium in Kingston. The 200 starts Saturday and wraps up Sunday.