Celtic interim boss Neil Lennon feels the Hoops has noted how Ajax have pushed the boat out in terms of transfer fees, while having a similar wage budget to the Hoops, and have reaped the rewards.
The Dutch side shocked Champions League holders Real Madrid in the Round of 16 and reached the quarter-finals of the competition for the first time since 2003.
Celtic had a run in the Europa League earlier this season as they made the knockout stages before losing to Valencia, but the side have struggled to impose themselves at Champions League level in recent seasons.
Lennon feels Ajax have reaped the benefits of spending a bit of money to improve the overall quality of the squad, and that showed in the group stage as they remained unbeaten against Bayern Munich.
The former Hibs manager has also noted that the Dutch giants' wage bill will not be too far out of whack with that at Celtic Park.
"It was magnificent but they have spent a bit of money”, Lennon was quoted as saying by the Evening Times.
"Dusan Tadic has gone in there for £15m to £18m so maybe the wage bill is around what we have but they have definitely improved financially.
"But it is fantastic and it should be a great inspiration for clubs like us.
"It takes a bit of time to build teams for that level. It took me three years to really build a good team to compete at a good level and get through the group.
"This team, with a few more additions, would be capable of competing at that level again, at a good level.
"But congratulations to Ajax, it was a wonderful performance.”
Celtic are on course for an historic treble-treble as they have an eight-point lead at the top of the Scottish Premiership table, and are in the semi-final of the Scottish Cup.
