Back injury Rafael Nadal suffered in Australia, knocks him out of Rotterdam.
World No. 1 withdraws from Qatar Open.
Laver Cup Boston set for September 24-26th.
Spanish teenager will join 56-player field in Madrid Masters.
The LTA is hopeful fans will be permitted to return to grass-court events in June.
With spectators reduced, the tournament has had to shrink its prize money pool.
World No. 1 Novak Djokovic showed his mental strength is a major weapon, says Toni Nadal.
