It was almost as though Mathieu Flamini was spirited back to Arsenal under the cover of darkness. His Bosman return in the final days of last August, after his Bosman departure in 2008 to Milan, did not exactly quicken the pulse, coming, as it did, against the backdrop of those thunderous calls for lavish, A-list investment.

Here was a player who had previously walked out on the club; a blue-collar, no frills, midfield hustler. And he was coming on the cheap. From a PR point of view, it felt like a tough sell and there was no drum roll or grand unveiling for him. Happily for Arsenal, that would come when Mesut Özil joined for £42.5m from Real Madrid.

But the spotlight will pick out Flamini on Sunday, when he returns to the Arsenal team for the FA Cup last-16 visit of Liverpool after a three-match ban and there is general relish about his involvement, not least from the 29-year-old himself.

Arsène Wenger is expected to rest the majority of his star names, as they lick their wounds after the exertions of Wednesday night's 0-0 draw with Manchester United and look ahead to next Wednesday's Champions League last-16 first-leg tie at home to Bayern Munich. Lukas Podolski will come in for Santi Cazorla, who Wenger said was feeling ill anyway, while it would be a major surprise if regulars Mikel Arteta, Jack Wilshere, Özil or Olivier Giroud were to start the match against Liverpool.

Flamini stands to shoulder great responsibility, which is a tribute to the impact that he has made this season. Never go back? Not in Flamini's case. He has been a pivotal player for Arsenal in the Premier League and Champions League, and the statistics support him strongly.

When he plays, Arsenal score much more, they concede less and they win much more. According to Opta, the club's win percentage with Flamini in the team is 72.73%; without him, it is 50%. As an aside, he has the highest pass completion ratio of any midfielder in the Premier League, his 92.38% narrowly eclipsing Arteta in second, which speaks volumes for his reliability.

Flamini, though, is on a mission to atone for one major blot on his season, the rush of blood that saw him sent off in the 2-2 draw at Southampton on 28 January. He has previous for two-footed tackles – he was guilty of a horrible one on Tottenham Hotspur's Vedran Corluka for Milan in the 2010-11 Champions League – and he should have known better than to jump in at Southampton's Morgan Schneiderlin last month. It was the 99th red card of Wenger's Arsenal tenure.

Flamini crossed the line at Southampton but he has previously impressed in pushing all the way up to it. He brings a spikiness to the team, which the likes of Cesc Fábregas and Robin van Persie used to do. The former club captains could be demanding but in a good way.

Flamini loves the "dark role," according to Wenger. He is a scrapper; the Hong Kong Phooey to Özil's Pink Panther. Above all, he is the balancing ingredient to a line-up that is heavy on creative players. "We looked sometimes, in the big occasions, a little bit afraid defensively," Wenger said recently. "Flamini gives us something more."

Arsenal have been feted for their defensive assurance this season, apart from in the thumping league defeats at Manchester City and Liverpool, and Flamini, the screen in front of the back four, has been a factor. Tactically more savvy after his five years at Milan, where he won the Serie A title in 2011, his experience at pressure points is a boon, and this is a pressure point for Arsenal.

"He gives us that little bit more stability at the back," Wojciech Szczesny, the goalkeeper, said. "He also gives some of the other players more freedom to attack. He's a terrific player. He's been great for us."

"He gives us sometimes a balance between offence and defence," Wenger added, " ... but especially when Arteta is not there because Arteta is a tactical brain. Flamini, as well, is good tactically so you need always one of the two."

Wenger disputes the notion that Arsenal have missed Flamini since his ban. They beat Crystal Palace 2-0 at Emirates Stadium before the 5-1 loss at Liverpool and the home blank with United, and Wenger reverted to his 'special circumstances' routine to explain away Anfield. The first two goals, he said, followed freakish set-piece lapses and Arsenal had no choice but to open themselves up afterwards. Away from home, against a good attacking team, the heavy result can happen.

But Flamini's comeback feels timely, particularly as Arteta endures a lull. Flamini is the only surviving link on the playing side to Arsenal's last trophy – the 2005 FA Cup – although he was not in the squad for the penalty shoot-out victory over United in the final.

Wenger talked up the importance of Liverpool's visit. They were the "first team" Arsenal wanted to play, he said, rather than the last and revenge for the 5-1 would be at stake. How Arsenal fared in the cup, he added, would impact the club's fortunes in the other competitions and the temperature has been raised by the reaction of the Emirates crowd to the United stalemate. Wenger admitted that he was surprised to hear the boos.

A test of strength looms. Flamini is ready.