Complex sentence: The following season he scored 19 (his best single season for the Gunners) and won the Cup Winners' Cup, but his form deserted him in 1994-95, and the arrivals of John Hartson and Dennis Bergkamp threatened his place in the side.
Split into simpler sentences: The following season he scored 19 goals in what was undoubtedly his best single season for the Gunners and as well won the Cup Winners' Cup. With this being so, his form deserted him in 1994-95, and the arrivals of John Hartson and Dennis Bergkamp threatened his place in the side.