The first on the list, and the worst performance by far, came at the Riverside against Middlesbrough. Arsenal were deservedly beaten 2-1, and even that scoreline flattered the Gunners.
There were lots of issues that day, but Gilberto's play continues to stand out in the mind a month later.
Gilberto spent most of the game passing backwards and hoofing longballs to the front. When he did pass along the ground, his balls were leaden, ineffective, and often intercepted by the Boro midfield.
To make matters worse, he was partnered with Lassana Diarra—and Gilberto necessarily reduced the quality of the Frenchman's performance.
Diarra has skill, there's no doubt about that. But he has to be partnered with a creative midfielder who can take advantage of his work rate and endurance—which is why Diarra fits in so well with the French National Team, where he's surrounded by creativity, and can work seamlessly as a link man
Diarra has been strong when he's been partnered with Cesc Fabregas or Denilson. But when he's stuck in the midfield with Gilberto, the Arsenal team bogs down into an uncreative morass.
And this phenomenon doesn't just happen to Diarra—it happens to all of Arsenal's less established players.
As was the case with Thierry Henry last year, Gilberto's presence inhibits the play of everyone else. When he turns to the safe back pass and slows down the tempo, the rest of the team follows suit.
The only bright spot against Boro was Thomas Rosicky, a player who's secure enough in his own quality (he is the captain of the Czech Republic, after all) to be unfazed by Gilberto's presence.
To be fair, Gilberto is a defensive midfielder. He is not and has never been the most offensive-minded Gunner (hell, I have a shirt that declares "I saw Gilberto pass forward").
When things are going wrong and he doesn't have an Henry or a Fabregas dictating the pace of the game, Gilberto falls back on safety and comfort. That's understandable—but it's also counterproductive for a team trained in fluency and attack.
Gilberto's greatest strength is his defensive fortitude. His greatest weakness is his inability to shift seamlessly to the attack.
And this was evident again during Arsenal's 1-1 draw at St. James' Park against Newcastle.
After Arsenal took the early lead off an Emmanuel Adebayor goal, Gilberto slowed things down, playing right into Newcastle's hands.
Again he was partnered with Diarra, and again the Gunners ground through the game with no inspiration.
Gilberto wasn't terrible—he never is—but he was more effective at countering Arsenal's attack than was Newcastle's defense.
Then there was Arsenal's FA Cup tie at Burnley on Sunday.
Arsenal came out 2-0 winners against the Championship side, but the match really should have been a repeat of the Gunner's 2-1 loss at Boro.
Eduardo scored an early goal on a chipped pass from Kolo Toure—which makes one wonder why Arsenal's center back has to create chances when Gilberto is in the midfield.
It should be the role of the Brazilian World Cup winner or his understudy Denilson—but Toure had to bomb forward to make the pass, as the midfielders were nowhere to be seen.
Regardless, the Gunners took the lead—then quickly slipped into Gilberto's comfortable second gear.
Gilberto sat in the midfield and led the Gunners into lethargy. Long balls started flying, and back passes became the norm rather than the exception—and Gilberto was the hub of it all.
And so a game that should have seen a flood of scoring became a boring grind that could easily have gone the other way.
As I see it, not enough has been made of Gilberto's displacement in the midfield by Mathieu Flamini. Many think the shift is like for like, but that's simply not the case.
There are a number of reasons Flamini has taken Gilberto's spot, but most importantly, Flamini gives up nothing in defense while adding the ability to transition into the attack.
Flamini fits the style of football Arsene Wenger has created: Attack, attack, attack...and defend to attack again.
Flamini does it. Gilberto does not. And that is why Gilberto is no longer Wenger's first choice to partner Fabregas
Don't get me wrong—I love Gilberto, and I loved what he did for us last year while Henry was hurt. But that's not enough.
No, he's not solely to blame for Arsenal's poorest performances this season, but he has to take a huge portion of responsibility.
There's no avoiding it and no denying it, no matter how much it hurts: Gilberto is no longer an Arsenal man. The team has changed, and he no longer fits.
It doesn't matter that Gilberto is the captain of Brazil. It doesn't matter that he was part of the Invincibles. It doesn't matter that he's a likable guy and a consummate professional.
He needs to move on.