London - Jurgen Klopp has risked Arsene Wenger's wrath ahead of Liverpool's visit to the Emirates Stadium by claiming the Arsenal manager failed to get the best out of Alex Oxlade-Chamberlain.
Oxlade-Chamberlain joined Liverpool in August after Wenger decided to cash in before the England midfielder's contract expired.
The 24-year-old never quite lived up to his early promise at Arsenal after his switch from Southampton.
But, after a slow start at Liverpool following his ($46 million, 39 million euros) move, Oxlade-Chamberlain has started to hit his stride in recent weeks - just in time for his first return to Emirates on Friday.
Reds boss Klopp has been impressed by Oxlade-Chamberlain's development at Anfield, saying: "He had to adapt. I know how it is if you're kind of a big signing.
"You have to perform immediately. But it's difficult.
"I was happy from the first day about his involvement, about his attitude, and since then he became more and more a Liverpool player."
But Klopp believes Oxlade-Chamberlain would already be an even more potent force if he had been instructed to add a goal threat to his game while he was with Arsenal.
Oxlade-Chamberlain has scored just twice in 20 appearances for Liverpool and managed 20 goals in 198 games for Arsenal.
Klopp believes that poor strike rate is down to Wenger prioritising the talents of Alexis Sanchez and Mesut Ozil.
"I think the biggest improvement, or the biggest potential he still has, is really being involved in goalscoring situations, because he has it in himself," Klopp said.
"It is unbelievable, but he was not asked for this too much I think in the past.
"If you watched Arsenal in the past, the two decisive players were Sanchez and Ozil.
"In a lot of moments, the decisive passes, Ozil or Sanchez. Then you are not that much involved.
"Here, we put it on much more shoulders, and if he's on the pitch he needs to be involved in situations like this.
"I see really a lot of space for improvement as well, and that's good."
As if that wasn't enough to irk Wenger, Klopp also made a point of highlighting how the Frenchman, so renowned for his purist principles, has often used a far more rudimentary approach against Liverpool based around the aerial ability of Olivier Giroud.
"Against us most of the time Giroud played from the beginning, so that says a little bit about the style of Arsenal they have chosen against us very often," Klopp said.
"They are a complete football team, able to do everything. They can switch and change styles.
"Against us it happened quite often that they played a lot of long balls, with Giroud. But he cannot play on Friday and that will change a few things maybe."
With Manchester City running away with the Premier League title race, the focus at the Emirates will on the battle for a top four finish.
It is a crucial clash for both sides as fourth placed Liverpool are one point ahead of fifth placed Arsenal in the battle to qualify for the Champions League.
Wenger made it clear how important Liverpool's visit is when he made 11 changes for Tuesday's 1-0 League Cup quarter-final win over West Ham.
Liverpool haven't played since Sunday's thrashing of Bournemouth and Wenger is concerned the hectic fixture schedule is taking a toll on his team after Giroud was sidelined with a hamstring injury.
"It is very demanding, especially because we already have a tough schedule behind us," he said.
"We have to sit down and analyse very well what we can do. What is very worrying in my job is when you start to lose players like Giroud.
"After, you cannot afford to lose another one. I have to look how I can manage the schedule."