ABEL XAVIER ended his second spell at the Riverside Stadium yesterday, with his departure increasing the pressure on Middlesbrough manager Gareth Southgate to step up his pursuit of a new full-back.

Xavier's failure to receive the salary he felt he had earned with his performances this season has led to an early parting ahead of Sunday's final Premiership fixture at home to Fulham.

And with Stuart Parnaby's contract wrangle appearing to be heading for a similar ending, Southgate will be left with just Andrew Davies and Tony McMahon to play that role.

Parnaby has already turned down improved terms with the club he has been with since his Academy days, with Everton, Hull City and Celtic all keeping a close eye on the defender's situation.

With Southgate likely to be left short on defensive options before pre-season training begins, he will be looking to make moves for new players as soon as the season ends.

It is a position he has been looking to strengthen for some time with the departure of Xavier - a controversial figure during his time in the North-East - making the matter more pressing.

In January Southgate explored the possibility of signing Colchester's highly-rated Greg Halford, only to be put off by the £4m price-tag and Middlesbrough were eventually beaten to his signature by Reading.

And the Boro boss has also had Porto's versatile Jose Bosingwa watched, with the right-footed full-back also capable of playing on the wing and in central midfield.

Southgate's primary concern remains Mark Viduka's situation, although the departure of Xavier will reaffirm the need to strengthen across the Middlesbrough squad.

Xavier, whose last appearance was the 3-1 defeat to Aston Villa on April 14, only tasted victory in the Premiership on four occasions during his second spell on Teesside.

The 34-year-old will be returning to England later today to hold talks over possible moves back to the Premiership, with Portsmouth manager Harry Redknapp an admirer of the Portugal international and a possible suitor. He is unlikely to return to Portugal.

Xavier's departure was very amicable, although he would have stayed had Middlesbrough offered him the terms he felt he deserved.

"I would like to say thank you to Middlesbrough Football Club and to the chairman Steve Gibson, who is a great person, enthusiastic and someone who wants to take the club forward," said Xavier.

"Thank you also to Keith Lamb (chief executive) and to the manager Gareth Southgate for the support they gave me in my time at Middlesbrough.

"Gareth has my respect as a person and as a coach. We have not reached agreement to extend my contract but I accept that decision. We move in different directions but with mutual respect.

"Gareth Southgate is the correct person to take the club forward because he has respect as a person and as a coach. That is a great quality because most of the time this does not happen with players that become managers, as they lose respect towards the players.

"When this kind of thing is missing the players do not show respect to the manager but this is not the case with Gareth."

And Southgate admitted a personal disappointment that a compromise could not be reached with the former Liverpool and Everton defender.

"I am disappointed Abel has decided not to stay with us," said Southgate. "But I'd like to thank him for his contribution to the club. He always did well when called upon and we wish him all the best."

Xavier's first spell with the club ended in disgrace. In September 2005 he tested positive for a banned substance after Boro's UEFA Cup date with Greek side Xanthi.

UEFA suspended him from the game for an 18-month period, reduced to 12-months on appeal, although Xavier always protested his innocence.

After serving his ban, he was given a chance to prove himself again last November at the Riverside - something he remains thankful for - and he hopes the supporters who have stood by him will stand by Southgate.

"To the Middlesbrough fans, a special message that they must support the club and stick with Gareth," he said. "You have a good chairman who supports the manager. The supporters must be part of the same objective.

"Personally, I would like to say thanks for their support to me because the fans are very passionate about the club and are anxious for success and I hope the club achieves that. Middlesbrough is always going to be a special club to me."