Less than a week ago, Redknapp claimed he would not be doing any business this month but has since seen midfielder Sandro and central defender William Gallas join the club's injury list.
And he is still casting an eye over Krul, who he rates as "a world class keeper".
Several of the papers on Friday morning have hinted at a double swoop on Blackburn for Chris Samba and Junior Hoillet.
With Spurs now just six points adrift of leaders Manchester City and three behind Manchester United with a game in hand on both clubs, the White Hart Lane side are firmly in the title hunt going into the second half of the season.
Harry Redknapp: "If you'd told me six months ago that my Spurs side would be right in the mix for the title, I'd have laughed.
"And if we could find a couple of new faces to improve us even further over the next month, then who knows where this season could take us?
"The problem we have now when we look for players is that the better you get, the more difficult it is to find someone who will take you even higher.
"Believe me, there aren't that many out there - but we won't fall down on that score through a lack of looking.
"I'm not about to say the Premier League is coming to Tottenham because there are still so many who could have a big say.
"And it doesn't take a genius to point out that Manchester City are still red-hot favourites, while anyone ready to write off United needs their head looking at."