For the best part of a year Alexis Sanchez and Mesut Ozil have appeared incapable of flexing anything with quite the same sort of purpose with which they flexed the threat of the Bosman free transfer.
Since they clambered victorious to the top of the charts for the Premier League's best-paid players, in fact, they have vanished almost entirely from the highlights reels and the goal rankings.
Unai Emery has virtually given up on Ozil who was unable to turn the tie with a late cameo appearance on Friday night and is available on loan with Arsenal prepared to subsidise his enormous wages if anyone is interested.
Alexis Sanchez scored against his old club as Manchester United beat Arsenal on Friday night
Sanchez, too, has proved to be variously anonymous, absent, unsettled and unfit since his move to Manchester United.
There was, however, a certain sense of inevitability among the natives at the Emirates Stadium that this would be the night when he became relevant once again.
Sure enough, little more than half an hour had ticked by when Sanchez seized on a pass by Romelu Lukaku, danced around Petr Cech and scored for the first time since early October.
A year has passed since his Manchester United debut at this same stage of the FA Cup, a comfortable win at Yeovil, after which Jose Mourinho hailed the Chilean for his 'maturity and class'.
Mourinho was still basking in the audacity of the transfer coup.
United had beaten Manchester City to his signature and Sanchez pocketed a £6.75million signing-on fee and an annual salary of £20.35m plus bonuses at Old Trafford.
Chilean Sanchez dinked the ball over goalkeeper Petr Cech to open the scoring in the Cup tie
He was handed fabled No 7 shirt and made the awkward star of a cheesy unveiling video, tinkling at the ivories of an upright piano.
It was that sort of a transfer window, but none of this went down well at Arsenal, where they once hung a banner in honour of Sanchez and his pet dogs Atom and Humber.
They longed to keep a player who scored 80 goals in 166 games over three-and-a-half years and distracted from deeper problems, and someone thought the dog banner might appeal to his sense of loyalty, which was almost as laughable as the piano stunt.
So they jeered his name when the teams were announced on Friday night and
