Former Rangers captain Barry Ferguson has claimed that the club's new signings will need to adapt quickly to the "tough" football of the Scottish Premiership.
New Blues manager Pedro Caixinha has recruited eight players so far in the transfer window, seven of whom are from overseas.
Ferguson, who had two spells at Rangers, suggests that footballers not familiar with the Scottish top flight may be taken aback by the type of game played and the level of expectation on them.
"These guys will need to get up to pace pretty quick," he told BBC Sport. "There's no doubt in my mind that they're good players.
"It's a bit easier to a certain extent at Ibrox where there's a bigger pitch and you've got 50,000 fans behind you but when you go to the smaller grounds, where it's tighter, the pitches aren't as good, they get the fright of their life. It's 100-mile-an-hour stuff.
"If you're not up for the fight, when you go to places like Easter Road or Tynecastle or Fir Park, these guys are going to run over the top of you. They're used to a different type of football. Scotland is a tough, tough, tough place to play football."
Portuguese players Bruno Alves, Fabio Cardoso, Dalcio and Daniel Candeias, as well as Colombian striker Alfredo Morelos and Mexican duo Carlos Pena and Eduardo Herrera, have joined Scottish midfielder Ryan Jack in moving to Ibrox this summer.