Anderson has been ruled out of Thursday's fourth Ashes Test at Trent Bridge, Broad's home ground, with a side injury suffered during England's convincing eight-wicket win over Australia in the third Test at Edgbaston last week that put them 2-1 up in the five-match series.
That match saw Anderson take an Ashes-best six for 47 in Australia's first innings as he again underlined his worth to England.
No wonder many Australia players have likened Anderson's injury to the moment Australia pace great Glenn McGrath trod on a stray ball before the start of the 2005 Edgbaston Test and was ruled out with an ankle injury which also sidelined him from the fourth Test of that series, at Trent Bridge.
England won both matches McGrath missed that series as they regained the Ashes 2-1.
Also Read
"I don't think there's been too many cases in history where a guy has 299 wickets and played 80-odd Tests and he's waiting to lead the attack," Cook said Wednesday.
"It's a great moment for him in terms of his homeground and stuff.
"Clearly Jimmy is going to be missed, we can't sit here and deny that.
"You don't play forever and think 'who is irreplaceable'? There's always someone who can come in."
Middlesex fast bowler Steven Finn was the man who stepped up at Edgbaston, marking his first appearance at this level in two years with a Test-best six for 79 in Australia's second innings after replacing the injured Mark Wood.