Ibrox side Glasgow Rangers have made eight new signings so far this summer.
Foderingham was Rangers’ first-choice stopper last campaign, as they earned promotion back to the top tier, while Kranjcar has only recently signed up for the Ibrox side.
Rangers have been back in pre-season training for just over two weeks now.
And Warburton said: “The very first day Matt Gilks had in training, we saw a reaction from Wes Foderingham right away and that’s what we want. We need good players coming in.
“I’ve seen Niko Kranjcar in training and he looks excellent. He will put pressure on Andy Halliday and Jason Holt in midfield.”
Rangers are currently in America training, as they gear up for the start of the competitive campaign.
Rangers’ league season begins on 6th August, when they take on Hamilton at Ibrox.
Foderingham and Kranjcar both seem likely to start in Warburton’s side’s first match of the term, providing they continue to impress over pre-season.
Rangers have already made eight new signings this summer, and more additions are set to follow in the coming weeks.
The Light Blues’ first friendly match on their tour of the United States comes on 6th July against Charleston Battery.