aljaz bedene officially became a british citizen at a ceremony on tuesday .
the 25-year-old is currently ranked no 83 in the world but will be gb no 2 .
andy murray says fellow british players like james ward and kyle edmund should not complain about the assimilation .
bedene was born in slovenia and could rise up the rankings , says murray .
british no 1 insists young stars should use bedene as motivation .