The npower League Two minnows threatened to add Keane's side to their list of cup upsets this season when Liam Davis fired them ahead early on but the hosts soon regained control. Carlos Edwards and Damien Delaney overturned the deficit before the break and a late Tamas Priskin header added some gloss to an ultimately comfortable win.
Keane said: "People think I'm doom and gloom but you look at Cardiff last night and we are a world away from that."
Ipswich have lost their past three league games to slide down the table and Keane is determined to add to his striking options. A move for West Brom striker Ishmael Miller remains an option but Keane is doubtful of luring him to Portman Road.
He continued: "We are miles away from the likes of Cardiff and QPR and people need to realise that. I appreciate my glass is always half empty but that is the reality.
"We are asking young lads to fill in and I am trying to get attacking players in. Ishmael Miller will have plenty of options. We are in the market and if you think we are the only club in for a player like him then you are mad.
"He is a good player and good players are always in my thoughts. I don't think we'd be the first option for players from Premier League clubs in the midlands or the north west. We have trouble attracting players down here as they don't often want to move away so we may have to look at younger players."
The Cobblers' form has nosedived since their famous win at Anfield in the previous round last month and manager Ian Sampson has now masterminded six straight defeats in all competitions.
His side face a vital league game at home to Gillingham on Saturday and the club legend admits that he is running out of time to save his job.
He said: "I did think it was going to be another one of those nights when we scored and that's only natural. It was a bit lucky with the deflection but you do start dreaming. It was maybe a bit early to go ahead but Ipswich's class shone through in the end."
Source: PA
Source: PA