Republic of Ireland legend Liam Brady has described retiring captain Robbie Keane as "a tremendous player for his country" and added that "we're going to find it very difficult to replace him".

Keane is to line out for Ireland for the final time against Oman next Wednesday, bringing to an end an international career lasting nearly two decades that saw him become both his country's record goalscorer and cap holder.

The 36-year-old has been a mainstay for every Ireland manager since Mick McCarthy, who handed him his debut in March 1998, and Brady admitted it will be sad not to see Keane featuring for the boys in green any more.

"It's a sad day, not to be seeing Robbie turning out for Ireland in the future," said Brady on RTÉ's Champions League programme.

"But it's not unexpected. He's played a bit part over the last year or so, but it's sad all the same because he's been a tremendous goalscorer and a tremendous player for his country and we're going to find it very difficult to replace him.

"I think the Euros showed that already. 

"But what a player. Eighteen years in international football says it all really. Well done."

Brady was part of the Ireland management set-up under Giovanni Trapattoni and got a close-up look at Keane's professionalism in that time.

"He was 28 when I got to work with him," Brady said. "So he knew his body well. He knew what he could do in training.

"The goal in Paris stands out for me, one that gave us a great chance to qualify for the 2010 World Cup.

"He was the kind of striker that always comfortable being in the position to score. You get players who panic, but Robbie loved that pressure of one-on-one withe the goalkeeper, and invariably scored a lot of goals. It was great to work with him."