Steve Coppell stressed the importance to Reading of striker Dave Kitson after he ended a five-month injury nightmare by scoring in the FA Cup win at Birmingham.
Kitson scored 22 goals last season and played a major role in the Royals reaching the Premiership for the first time in their history.
But he suffered a knee injury on the opening day of the season against Middlesbrough and subsequent setbacks have kept him out of action until the 3-2 win at St Andrews.
Reading boss Kitson scored the opening goal before a brace from Leroy Lita helped the Royals into the fifth round for the first in nine years.
Coppell said: "It's very pleasing to see Dave Kitson back on the field of play. He almost made it last week against Sheffield United but got injured in the pre-game kick-about.
"He has had a rocky road and it was good to see him get on the score sheet. It must have been a huge relief to him.
"He gives us an option up front which we haven't had. He gives a more aerial route if we need to use it and he is also evasive."
Despite Reading's progress to the last 16 Coppell is still playing down the significance of the FA Cup. He made seven changes from the side which played Sheffield United and will stick with the same philosophy in the next round.
He said: "The FA Cup is a very pleasant diversion but that's all. I am not dreaming of cup finals. I am a realist.
"We made changes for this game and it will be the same philosophy for the next round. Even so, this side still looked good on paper. It wasn't as if we were playing novices."
Birmingham boss Steve Bruce was left to rue his strikers missing a hatful of chances - a sharp contrast to their deadly finishing in the 5-1 win at Newcastle in the previous round.
Bruce said: "I don't think I can ever remember a game where we have created so many chances, especially in the first half.
"We had five or six great opportunities in the first 45 minutes. On another day it could have been another result like against Newcastle. You just have to accept it.
"That's why strikers get paid all the money, and today we missed our opportunities."
However, Bruce refused to trot out the old adage of now being able to concentrate on the Coca-Cola Championship after his side bowed out.
He said: "I have always relished this competition. There are too many people knocking it, it has been devalued and has lost some of its glamour.
"I am not going to trot out the old 'we can now concentrate on the league' line. This competition and the League Cup are our only realistic chances of winning anything."