Rangers manager Giovanni van Bronckhorst said his side will struggle to compete at Champions League level after a 4-0 thrashing by Ajax on Wednesday in their first group stage match for 12 years.

A run to the Europa League final last season and victory over Ajax's Eredivisie title rivals PSV Eindhoven in Champions League qualifying raised hopes Van Bronckhorst's men could challenge in a group also containing Liverpool and Napoli.

However, they suffered a chastening return to the top level of European football with Edson Alvarez, Steven Berghuis, Mohammed Kudus and Steven Bergwijn on target for the Dutch champions.

"To compete in the Champions League you spend hundreds of millions, for us to compete it is too much to ask," said Van Bronckhorst, whose summer signings amounted to just over £10 million ($12 million).

"We have to compete with the squad we have and are able and capable of making. We knew it was going to be tough and it showed today."

But the pressure is also mounting on Van Bronckhorst after Rangers were also blown away by fierce rivals Celtic 4-0 in the Scottish Premiership on Saturday.

"We knew the Champions League would be a high level and Ajax showed today throughout the game how good they are, how strong they are," added Van Bronckhorst. "You have to be 100 percent ready for the game."

Ajax brought in over 200 million euros ($199 million) in transfer fees for Antony, Lisandro Martinez, Sebastien Haller and Ryan Gravenberch in recent months.

However, they withstood interest in Alvarez late in the window from Chelsea and the Mexican opened the floodgates when he was left unmarked to head in a corner on 17 minutes.

Ajax look to have reinvested their transfer income wisely, including the signing of Calvin Bassey from Rangers.

The Nigerian international has been badly missed at the heart of Van Bronckhorst's defence in the opening weeks of the season.

James Sands has deputised at the back due to a number of injuries at centre-back and it was the American international who deflected Berghuis' shot into his own net to double Ajax's lead.

Just like at Celtic Park at the weekend, a two-goal deficit quickly became three for Rangers when Kudus's storming run concluded with the finish to match as he smashed in off the far post.

Van Bronckhorst responded with three substitutions at half-time and a change of system which helped stem the flow of Ajax attacks.

However, Rangers were still undone by another self-inflicted blow for the fourth when Bergwijn latched onto Ryan Jack's slack pass to round Jon McLaughlin and slot into an unguarded net for his eighth goal in seven games since returning to the Netherlands from Tottenham.