Lionel Messi has been included in Barca's squad despite being hurt during their 2-2 draw against Valencia on Saturday, but Mijatovic doubts any risks will be taken with the five-time Ballon d'Or victor. Messi didn't play in the first El Clasico of the season at Camp Nou and he will certainly be fighting to avoid missing another one due to injury.
Real Madrid coach Santiago Solari had said earlier on Tuesday that he hoped Messi would be available.
Messi missed Barcelona's 5-1 league rout of Madrid in October because of a broken right arm.
The Argentine superstar is expected to feature at some stage with his team going doing battle in the Copa del Rey semi-final first leg.
"In football it is good for the best players to play in all games", Solari said. "If he is fit, he will play and if he is not, he will not play".
Barcelona to play Real Madrid in Copa del Rey semifinals
The final will be on May 25 at Benito Villamarin Stadium in Seville, a 61,000-capacity venue that is home to Betis. Barcelona are now top of the La Liga table, with Real Madrid 10 points behind in third place.
Meanwhile, Los Blancos reached the last four, after securing an emphatic 7-3 aggregate victory over Girona.
The fact that these games seem more likely to define Madrid's season than Barcelona's says everything about the two clubs' current fortunes.
Five seasons ago Real Madrid and Barcelona did not play each other in the cup.
Benzema and Vinicius have wreaked havoc thus far.
"It was already complicated in January but with this semi-final at a very high level, more league games, more games in the Champions League knock-out stages, we have to walk a fine line". The 18-year-old Brazilian has added flair to the attack.
At left-back, Marcelo has been the starter in the Copa del Rey, yet Sergio Reguilon's form since the trip to Real Betis has been exceptional.