MARK Viduka has been told his World Cup place is under threat unless he plays regular first-team football between now and the end of the season.

The Middlesbrough striker has been conspicuous by his absence since rowing with a group of supporters in the wake of the 4-0 home defeat to Aston Villa.

He was left out of Steve McClaren's 16-man squad for last week's FA Cup win over Coventry and also played no part in Saturday's 3-0 win over Chelsea after complaining of an illness on his arrival at the Riverside.

McClaren has denied there was a hidden agenda to the striker's absence and, with the fixtures piling up as Boro chase success in two cup competitions, Viduka is likely to feature in this week's UEFA Cup clash in Stuttgart.

"Mark would have been on the bench on Saturday but he came in not feeling so well," said McClaren. "He saw the doctor at the stadium and I decided there was no point risking him."

With Australia having qualified for this summer's World Cup finals in Germany, Viduka can ill afford a lengthy absence from the first-team squad.

Despite skippering the Socceroos as they booked their World Cup spot with a dramatic play-off win against Uruguay, the former Leeds and Celtic striker is not assured of a place in his country's opening game of the finals against Japan on June 12.

Australia boss Guus Hiddink has warned all of his Europe-based players that they must be playing regular football in order to be considered.

Viduka has now gone eight games without playing a full 90 minutes for the Teessiders and has only scored once in his last 16 appearances.

His leading rival in the Australia squad, John Aloisi, is enjoying a rich vein of form in La Liga. The former Coventry striker has scored five goals in five games - including a second-half strike against Malaga last weekend - as his club side, Alaves, have pulled clear of relegation.

Meanwhile, Barcelona boss Frank Rijkaard is hoping to call on McClaren's help as he attempts to heap more misery on Premiership champions Chelsea.

The two sides meet in the last 16 of the Champions League next week and, after learning of Boro's three-goal success against the Blues, Rijkaard has promised to give McClaren a call.

"I'm going to ring the manager of Middlesbrough so he can tell me how they won," he said.

Boro's UEFA Cup opponents Stuttgart have appointed Armin Veh as a replacement for former manager Giovanni Trapattoni, who was sacked last week.

Veh has taken over until the end of the season, but was unable to prevent Stuttgart losing 2-1 at Armenia Bielefeld last weekend. They have only won two home games all season.

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