Everton manager David Moyes believes Arsenal are benefiting from the years of Mikel Arteta's development spent under his guidance.
The Spaniard left Goodison Park for the Gunners in a £10million deal on the final day of the summer transfer window last year after six years playing for the Scot.
Moyes admits when he first brought in Arteta from Real Sociedad, after a two-year spell with Rangers, he was unsure how well he would fare.
However, he now sees Arteta as a key player and one of the leaders in Arsene Wenger's side, the visitors on Wednesday night.
``I'm not surprised. He is a very gifted footballer, he is a great lad to work with,'' said Moyes.
``I think the manager (Wenger) was probably surprised what he offers: he is a great professional, a really good footballer and I'll be delighted to see him back - just disappointed it is in an Arsenal jersey.
``I see Mikel now and when they are having a bit of a huddle he is the one who is the leader and I think they look to him, he has taken on a lot of the leadership qualities in that side.
``He was part of the rebuilding process that had to take place at Everton when we tried to develop the team and move it on.
``We took Mikel on loan from Real Sociedad after he'd been at Rangers and it hadn't quite worked for him.
``We were a bit unsure when he first came here. He was a bit lightweight to play in the middle and so we played him off the side and he was great there for us, he really was.
``Eventually he moved on to be a real key figure in that period and was a big part of us developing and moving Everton forward.''
Arsenal were the last team to beat the Toffees at Goodison in the league, last March. Since then they are 10 unbeaten on home turf.
Everton midfielder Marouane Fellaini returns from suspension to face the Gunners.
Moyes is still waiting on Darron Gibson, out since early September because of a thigh problem, as he approaches full fitness.
Seamus Coleman, Victor Anichebe, Phil Neville and Kevin Mirallas were all unavailable for Saturday's draw with Norwich and Moyes expects to pick a similar team.
Meanwhile, Arsenal manager Arsene Wenger has vowed that the club will spend their new £150million sponsorship cash from Emirates ``in the right way''.
Despite not having won a trophy since the 2005 FA Cup, the Arsenal brand remains strong and long-term partners Emirates Airlines last week agreed a lucrative sponsorship extension which will earn the club around £30million a year.
Some of that revenue has been frontloaded to come in the current financial year and so increase Wenger's summer transfer budget, which has already been boosted by the £24million sale of former captain Robin van Persie to Manchester United.
However, Wenger insists Arsenal are not about to break the bank for a marquee signing.
``If we get that amount of money from sponsors it is not charity, it is because the sponsors feel that we act in the right way and with the right values. They reward that,'' Wenger said.
``Afterwards it is down to us to spend the money in the right way.
``There are two aspects to any deal; one is the transfer [fee] and the other is the wages.
``The transfers for these kinds of players are not at £30million today, they are at £50million or £60million and what has gone through the roof is the wages of these players.
``That is why people plead for financial fair play. Some clubs even pleaded that the new television money (for Premier League clubs) should not be used to increase wages because it gives huge problems to everybody.''
The Gunners will have forward Theo Walcott back from a shoulder problem.
Czech midfielder Tomas Rosicky (Achilles) is back in full training after his long injury lay-off, but will not feature at Goodison.
Defender Andre Santos (stomach muscle) remains out, while midfielder Abou Diaby (thigh) continues his rehabilitation.