Former Monaco defender Leonard joined the club last week on a two week trial and Brown admits so far the coaching staff have been impressed.
"He does look the part, he is big in stature and willing to learn. One of his major advantages is that he is all left footed which is good because we haven't a left footed central defender at the club" he told www.bwfc.co.uk
"Phillippe has great potential and is eager to play in the Premiership, Obviously if he continues to impress in the trial, which culminates in a practise match on Thursday amongst members of the squad, we'll make a decision on him then."
Brown is also hoping that the 29-year old Belgian international is much more successful than the succesion of trialists which the club have taken on since the injury to Florent Laville last month.
"We have seen a lot of trialists at the club in the last few weeks, and none have come through so we will have to make doubly sure that he is good enough to play at this level".
Vargas on the other hand did not do enough during his trial period and it is thought that the former Reggiana defender will now move back to South America in the search for a new club.
"He is no longer with us after spending the last week at the club" Brown confirmed
"He played a game behind closed doors and we judged him on that, we felt that he wasn't up to the standard that we where looking for"