The Magpies are currently 19th in the table and fighting against relegation this season, following a disastrous campaign.
Their hopes of avoiding the drop were handed another huge blow on Saturday as Southampton enjoyed a comfortable 3-1 victory at St Mary’s.
The defence took the brunt of the blame once again as they committed schoolboy errors throughout the game to hand victory to the Saints.
Sinclair though, says that they cannot take all the blame and insisted that the midfield must also be criticised.
“You can’t just blame the Newcastle defence,” he told BBC Sport. “There’s a midfield who should be protecting them – away from home, lacking confidence, they’re not getting back to help the defence out.”
Despite what Sinclair says, Newcastle United’s failure to improve the defence certainly has been one that has haunted them this season.
Rather than spend big money in the summer transfer window and then again in January, they failed to significantly strengthen the defence and instead focused on other areas of their teams.
Considering they conceded 63 last season, and currently sit on 61 for this season, that has proven to be a huge mistake in hindsight.