Complex sentence: He impressed the national selectors by scoring 50 runs in his Test debut, However it did not cement his place in the national squad, throughout his career because he was competing with another Pakistani wicketkeeper, Moin Khan.
Split into simpler sentences: He impressed the national selectors by scoring 50 runs in his Test debut. This however did not cement his place in the national squad as he was throughout his career in competition with another Pakistani wicketkeeper Moin Khan.