The Ibrox skipper hailed the Honduran's debut in the 5-1 rout against Arbroath - even though he stole the show by bagging his second successive hat-trick. McCulloch said: "Arnold was fantastic. He has a bit of everything and will grow in stature the more games he gets.
"He has got to gain experience of playing in Scotland and of playing in front of so many fans and when he does I think he will be a top player for us."
McCulloch was delighted to score his back-to-back treble.
And two of the Gers captain's second-half goals were set up by pinpoint crosses from Honduran internationalist Peralta.
It was a remarkable contribution by the right-sided midfielder given that it was his competitive debut for the Govan club he joined in the summer.
But McCulloch felt the player was not operating at 100 per cent after being away on international duty with his country the week before.
He said: "He hasn't played a competitive game for a while and he had also done a lot of travelling in the days leading up to the game.
"I don't think Arnold played for Honduras in their World Cup qualifiers, but travelling the sort of distances that he did would certainly have taken it out of him."
Meanwhile, McCulloch has warned his Rangers team-mates they must perform better than they did against Arbroath - despite the comfortable victory.
Paul Sheerin's team dominated the opening 45 minutes and deserved to take the lead through Alan Cook early on in the second half.
The part-time Gayfield club caved in towards the end of the match and their hosts scored two late goals.
With nearest rivals Dunfermline and Stenhousemuir both drawing, Rangers moved five points clear at the top of the League One table.
The Light Blues have now scored 23 goals and conceded just two goals in their five league outings so far this season.
But McCulloch, who scored five headers in the games against East Fife and Arbroath, believes they must perform to a far higher standard.
He said: "I think the scoreline flattered us.
"We got all our goals in the last half an hour or so of the game. That tells its own story."