Complex sentence: Lehner was considered to have been one of the best outside rights of the 1934 World Cup in Italy, others touted him "the best non-professional player in Europe" (as professionalism was not allowed in Germany in the 1930s).
Split into simpler sentences: Lehner was considered to have been one of the best outside rights of the 1934 World Cup. Others touted him as "the best non-professional player in Europe" (professionalism was not allowed in Germany in the 1930s).