Middlesbrough midfielder Julio Arca's season has come to a premature end after he was allowed to return to Argentina to undergo knee surgery.
Arca is to have an operation to repair his meniscus cartilage and will, therefore, miss the final game of the npower Championship campaign against Doncaster at the weekend.
Mowbray told the club's official website, www.mfc.co.uk: "We let him have his operation early, that was the right thing to do so that he can be fit and ready for next season."
Arca's existing deal expires at the end of the campaign, although manager Tony Mowbray is hopeful he can persuade him to stay.
Meanwhile, striker Scott McDonald could return to the squad after missing the last two games with a hamstring problem.
The Australia international limped off during the 4-2 win at Hull having scored a first-half hat-trick.
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