Rangers manager Walter Smith admits he may have to tweak his tactics to worry Sporting Lisbon in the first leg of their UEFA Cup quarter-final.Smith's cautious approach has reaped dividends this season with his side chasing a quadruple trophy success.

They have already won the CIS Cup and are hot favourites to add the Scottish Cup and Scottish Premier League title to their trophy cabinet.

But Smith admits he may have to inject a fresh look into his solid formation at Ibrox on Thursday against a side he fears will have all their focus on their games against Rangers.

The Gers survived an onslaught in Germany to beat Werder Bremen 2-1 on aggregate in the last round, after a tight goalless draw against Panathinaikos at Ibrox was followed by a late equaliser in Athens.

Smith told Rangers World: "I don't think we could find a more difficult tie than the last round against Werder Bremen. In both legs we had to work extremely hard.

"This time we hope we can cause Sporting more problems than we did do Werder Bremen.

"The knockout games have worked well for us. After going 1-0 down against Panathinaikos for instance we had by far the best of the second half.

"Sometimes I think the defensive aspect is a little bit exaggerated.

"If you look at the second half of the Panathinaikos game we pushed forward a lot and actually played well.

"We have a way of playing that has been successful in knockout tournaments and we won't vary very much from that.

"But we know we may have to change the formation and tactics to try to cause Sporting problems."

However, Smith admits concern that Sporting will be determined to keep their season alive given their fifth-placed position in the Portuguese league.

"They have individual players who can cause any team problems," the former Scotland boss added.

"They have had a little bit of an indifferent season by their own high standards. They lost a number of players in the last close season.

"They had a little problem gelling together to find the consistency they had in the championship the previous season but I still think they have a capability in any given game to be an extremely good side.

"Their focus will be on the UEFA Cup now that the championship is well beyond them, and that makes them extremely dangerous.

"When you are going on all fronts the games are coming thick and fast and it's difficult to change from one aspect to another but we are delighted to be in the UEFA Cup at this stage and we look forward to the games."

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