Trapattoni gave Whelan his Republic debut in May

Glenn Whelan will play a vital role for the Republic of Ireland on Saturday - even though he has been sitting on the bench for Stoke City in recent weeks.

Giovanni Trapattoni gave Whelan his Irish debut back in May and the midfielder will earn his fourth cap in the World Cup qualifer against Georgia.

"Coming to meet the squad for the first time, you want to impress and catch the manager's eye," says Whelan.

Trapattoni has even compared Whelan to Italian midfielder Gennaro Gattuso.

Whelan says that the comparison has boosted his confidence but he knows that he faces a stiff challenge for the central midfield role from the likes of Andy Reid and Liam Miller.

"If I play badly in the next game, that could all go out the window.

"I'm here on merit, but I know that if I'm not doing the business, there are other players out there who will come in and take my spot."

Whelan will hope a positive result and a good personal display in Mainz will see him keep his place when the Republic play Montenegro in Podgorica four days later.

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The arrivals of Seyi Olofinjana and Amdy Faye has led to Whelan losing his starting role at Stoke in recent weeks.

Whelan is optimistic that he will be back in the Stoke team soon and good performances for his country may help his cause.

"I'm more than confident that I can get back in the team. I just have to keep my head down."

In the meantime, Whelan will hope to help his country get off to a good start as they attempt to book a trip to South Africa in 2010.

The Georgians will not have the advantage of playing in their own capital city of Tbilisi after FIFA ordered them to stage the game at a neutral venue.

Irish fans been allocated almost twice as many tickets as their opponents at the Bruchweg Stadium but Whelan says that will count for little once the first whistle goes.

"It is still 11 v 11 on the pitch. Hopefully, we will have a lot of support there, but it will be just like any other game."