Complex sentence: He scored his first goal for Celtic in the Old Firm derby match against Rangers on 18 September 2011 and made 6 appearances for the Scottish side before returning to Dynamo Kiev in January 2012.
Split into simpler sentences: He scored his first goal for Celtic in the Old Firm derby match against Rangers on 18 September 2011. Badr made 6 appearances for the Scottish side before returning to Dynamo Kiev in January 2012.