Kai Havertz's start to life in the Premier League has, so far, been mixed.

The 21-year-old attacking midfielder has played 10 times - scoring once in the league and four times overall - since joining Chelsea for £71m from Bayer Leverkusen in September.

But with manager Frank Lampard having used the Germany international in numerous positions already, it raises questions about whether the Blues have worked out how to utilise a player who provided goals and assists in abundance at his previous club.

So how can Chelsea, who face Rennes in the Champions League on Wednesday, get the best out of an undoubtedly talented youngster?
The many positions of Havertz - where have Chelsea used him?

Lampard has deployed Havertz as a right winger, a number 10 and even - on one occasion against Liverpool - as a central striker.

None of these roles are foreign to the German.

"For me, my best position is as a number 10, but I can play on the right side or as a striker," he said in September.

But the way he has often been asked to play those positions has been different from how it was when he excelled for Bayer Leverkusen and Germany.
Havertz: Leverkusen v Chelsea
Domestic season Pressures in middle & defensive thirds* Pressures in middle & defensive thirds* Touches in defensive third* Touches in opposition box*
2019-20 (Leverkusen) 5.24 7.03 5.79 5.46
2020-21 (Chelsea) 3.28 10.32 8.03 1.97
*per 90 minutes

This was clear from Havertz's debut against Brighton on 14 September, in Chelsea's opening Premier League game, where he played on the right wing of Lampard's 4-2-3-1 set-up.

The areas Havertz occupied on the pitch at the Amex Stadium rendered him ineffective, as he was often being asked to drop deep on the right side and try to build play.

This is best illustrated from his average position (number 29), which, incredibly, was deeper than N'Golo Kante (number seven), who was playing in midfield. This led to Havertz having no touches in the opposition box and failing to register a shot.

More recently, Havertz again played off the right wing in a 3-4-3 in the 0-0 draw at Manchester United on 24 October.

Theoretically, the system should have led to Havertz having more freedom to occupy advanced positions. However, he played in deeper areas of the pitch again, with his average position almost alongside wing-backs Ben Chilwell (21) and Reece James (24).

In fact, Havertz collected more passes (seven) from Chelsea centre-backs Cesar Azpilicueta and Thiago Silva than his central midfielders (five). The German again failed to attempt a shot or touch the ball in the opposing box.

Even when Havertz played as a number 10 in the 0-0 Champions League draw with Sevilla on 20 October, he had an early influence on the game in the final third but, as Chelsea's frustration grew, he dropped deeper and his influence waned.

Just 29% of his touches in the first 45 minutes were in his own half, but this increased to 45% in the second, and once again he failed to attempt a shot, which is at odds with a player who netted 38 goals during his final two seasons at Leverkusen.
Why is a deep role less effective for Havertz?

Interestingly, Havertz's deeper positioning directly cost Chelsea a goal in October's 3-3 draw with Southampton.

Attempting to dribble through the Saints' counter-press, he was dispossessed, allowing the visitors to tee up Danny Ings - and it highlighted how he isn't completely comfortable receiving the ball in such deep areas under pressure.
Havertz: Leverkusen v Chelsea
Domestic season Shots* Chances created* Expected goals* Expected assists*
2019-20 (Leverkusen) 2.13 1.94 0.33 0.23
2020-21 (Chelsea) 1.15 1.15 0.16 0.08
*per 90 minutes

Chelsea's third goal in the game provided the perfect contrast. They successfully played out of Southampton's press but this time Havertz's starting position was near the halfway line and he was able to make a run into the box and sweep home Timo Werner's cross.

In Saturday's 3-0 win over Burnley, Havertz lined up in a relatively unfamiliar role on the right side of a very attacking midfield three, once again being asked to contribute to deeper build-up play.

Almost 50% of his touches were within his own half and he almost cost Chelsea again, with his intercepted pass leading to Ashley Barnes firing narrowly wide.

This time Havertz had just one shot and two touches in the box.

How can Lampard get the Leverkusen Havertz?

During his final two seasons at Leverkusen, Havertz's attacking output took a significant leap.

This was a consequence of his natural development curve as a young player, but also the tactical responsibilities given to him by his manager Peter Bosz, who looked to use Havertz's finishing and ability to find a defence-splitting pass in the final third.
Havertz's last three seasons with Leverkusen
Starts Goals Assists Minutes per goal/assist
2017-18 26 4 9 206
2018-19 40 20 7 130
2019-20 44 18 9 141

Whether it be playing as a number 10, a right winger or, in his latter games, as a false nine, Havertz was always given the freedom to stay in advanced areas of the pitch.

At Leverkusen, he was averaging more defensive pressures in the final third, more touches in the opposition box and fewer in his own defensive third than he has so far at Chelsea.

He was also attempting more shots and creating more chances, while his expected goals rate and assist numbers were higher, most likely helped by a supply line of passes from central midfielders Kerem Demirbay, Charles Aranguiz and Nadiem Amiri.

The form of Chelsea's central midfielders - particularly how progressive they have been with the ball - has been questioned by some this season. Could Lampard call on the likes of Kante, Mateo Kovacic and Jorginho, to help unlock Havertz's potential?

Another key to Havertz's success at Leverkusen was surrounding him with quick wide players.
Havertz's midfield team-mates compared
Key passes* Progressive passes*
Demirbay (Leverkusen) 2019-20 2.34 5.83
Amiri (Leverkusen) 2019-20 2.62 4.66
Aranguiz (Leverkusen) 2019-20 0.98 7.32
Kante (Chelsea) 2020-21 0.14 2.17
Kovacic (Chelsea) 2020-21 0 6.67
Jorginho (Chelsea) 2020-21 1.22 4.08
*per 90 minutesKey pass = pass leading to shot without scoringProgressive pass = pass which advances the play

Wide men Moussa Diaby, Karim Bellarabi and Leon Bailey assisted 11 of the 18 goals Havertz scored last season and he returned the favour, with four of his nine assists providing one of the wing trio.

This is where some hope springs for Chelsea. Havertz has notched four goals and three assists when playing with one of Chelsea's quick wide men, Callum Hudson-Odoi or Christian Pulisic, although three of those goals came against Barnsley in the Carabao Cup.

If Lampard can find the right combination of midfielders and attackers, Chelsea can be hopeful of seeing the Bundesliga version Havertz shine for them this season.