End of season tensions have a variety of symptoms. The climax of 2010/11 has produced a novel one: footballers swearing in a very amplified way at nobody in particular.
First there was Wayne Rooney, who celebrated a goal against West Ham United that consolidated Manchester United's lead at the top of the English Premier League by voicing the sort of words parents discourage their children from using directly into a live television camera.
Now there's Zlatan Ibrahimovic, who collected his second red card in as many games for foul-mouthing at an assistant referee.
Ibrahimovic's offence, AC Milan's Swedish striker tried to explain after the Serie A leaders beat Fiorentina 2-1 on Sunday, was misunderstood. He had, he maintained, been swearing at himself, not at the official who reported the player to the referee who showed Ibrahimovic a straight red card for dissent.
The fact that Ibrahimovic had already received a booking which brought a one-match suspension means not much will be seen of the player for half of Milan's six remaining games.
Milan's top goalscorer for the season was, at Fiorentina, already making a comeback from a ban. He had been suspended for the two previous outings, including the Milan derby, for having planted his fist in the stomach of an opponent at Bari.
With all these days off, Milan would be entitled to ask what exactly they are receiving in return for making the striker the highest-paid employee at the club.
"I say sorry to my teammates," Ibrahimovic said after delivering his "swearing at myself" excuse, "it was a bad time to leave them with 10 men."
Indeed it had been. Ibrahimovic had been booked in the 77th minute, just before Javier Vargas pulled back a goal for Fiorentina; he left Milan reduced in numbers with three minutes, plus stoppage time left as the home team sought an equaliser.
It should be pointed out at this stage that Ibrahimovic had contributed substantially to establishing Milan's first-half lead, involved in the fluent moves that led to goals from Clarence Seedorf and Aleaxndre Pato.
Ibrahimovic has made a dozen assists in the league to go with 14 goals, which is one way to answer the question of what are Milan getting from their investment.
But, evidently, Ibrahimovic is not happy. He is an aggressive footballer, and on the evidence of his time at Inter Milan, at Juventus, at Ajax and particularly at Barcelona, the club he left last summer, he has bad moods and a sometimes brittle self-esteem.
Ibrahimovic has complained of tiredness at various times since the new year, which is not a plea that would be heard with great sympathy by the footballers who had long World Cup tournaments last June and July - Sweden did not qualify - but does seem to fit a pattern.
Last season, a wearying Ibrahimovic began to realise he was no longer essential to Barcelona's first team when he completed 90 minutes in only one fixture after the end of March.
And though the restless Ibrahimovic had contributed substantially to Inter's closing in on the 2008/09 Serie A title, he had been criticised for his lack of impact in the knockout stages of the Champions League, a competition he has never won.
That is a gap that Ibrahimovic has acknowledged gnaws at him, and no doubt the frustration grows when he sees the quarter-finals unfolding with Milan absent.
It is probable, too, that sitting out Milan's 4-0 win over Inter 10 days ago felt irritating, especially as Milan had appealed - in vain - to have Ibrahimovic's post-Bari ban reduced.
The fact that Ibrahimovic, who was the league's top scorer for much of the autumn, has registered only one goal since January, grates at his temperament. For the next fortnight, Milan, just like Barca were beginning to do 12 months ago, will have to plan without him.
