Arsenal are expected to make a number of signings in the summer transfer window.
The Gunners have come in for increasing criticism this season as the campaign will end without any sort of success.
At one point they had looked to be genuine Premier League title contenders as they topped the table at the beginning of 2016.
Instead a disastrous year so far saw them fall out of the running as Leicester City secured it for themselves.
Now they find themselves scrambling to secure a top four place and Sidwell, a former youth player at the club, believes they need to add a leader to their squad.
“They should have gone out and bought a striker in January,” he told Sky Sports.
“If they had done that then they would have been champions. Obviously there’s going to be a bit of a reshuffle in the summer.”
“I think a lot of the players have to stand up and be counted they’ve underperformed. You don’t see a leader in the Arsenal team, they need to install a little bit of steel in there.”
While who the club brings in is likely to be key, departures look likely to play a big part as well.
Already there has been talk of a number of players leaving the club, with the likes of Theo Walcott, Alex Oxlade-Chamberlain and even Aaron Ramsey all linked with potential exits.
Whether any do leave remains to be seen but what is certain is that the upcoming transfer window could be one of the biggest for the Gunners in some time.