US Open Tennis 2012: Watch Live Stream Online; Preview of Djokovic, Serena and More in Day Two’s Action

When and where: Tuesday's play at the 2012 US Open gets underway on all courts at 11 a.m. ET. Live streaming coverage will be available on USOpen.org. TV coverage begins on ESPN2 from 1 p.m., with a live stream available on ESPN3.

Preview: After all the big names came through their first examinations on Monday, another glut of potential challengers for the US Open title take to the court on day two at Flushing Meadows.

With Rafael Nadal unable to compete in the year's final Grand Slam through injury, the men's competition is widely seen as a three-way battle between Roger Federer, Andy Murray and Novak Djokovic.

While not always at their best, both Federer and Murray have safely ensconced themselves in round two following straight-sets victories. On Tuesday it is the turn of Djokovic , as he takes on Paolo Lorenzi to begin the evening session on Arthur Ashe Stadium.

After claiming the title in Canada, Djokovic suffered a convincing defeat to Federer in the final of the other pre-US-Open Masters 1000 event in Cincinnati. The second seed should have few problems, though, as he takes on 30-year-old Italian, Lorenzi.

Djokovic has won both of the pair's previous meetings, including at this year's Australian Open where he relinquished just two games.

With Nadal's absence, the door is firmly ajar for one of the other challengers to make a deep run to at least the semifinals. Very much in that mix is sixth seed Jo-Wilfried Tsonga. The charismatic Frenchman begins his US Open campaign against veteran Slovakian Karol Beck.

Tuesday also sees American Andy Roddick back in action on the court where he had his greatest triumph, Arthur Ashe. It is nine years since the soon-to-be 30-year-old claimed what still remains his only Grand Slam title, at Flushing Meadows. A second title seems further away than ever after a disappointing year that has many watchers of the game whispering the word "retirement."

Roddick's serve and forehand should still be enough to get the better of American qualifier Rhyne Williams and progress through to round two.

There is plenty of American interest on the women's side too, with both Williams sisters facing fellow country-women on day two. Venus is first up as she takes on the always interestingly-attired Bethanie Mattek-Sands. Now back ranked inside the world's top 50, unseeded Venus represents arguably the most dangerous floater in the women's draw. A semi-final run recently in Cincinnati shows that the 32-year-old is still capable of mixing it with the best on her day.

Sister Serena concludes the evening session later in the day against 20-year-old Coco Vandeweghe. Serena has shown in dominating victories at Wimbledon and the Olympics that when at her best there is no one that can currently match her unrelenting power and athleticism.

A stunning summer for Serena also saw her claim the title at Stamford, where she beat her opponent on Tuesday, Vandeweghe , in straight sets in the final.