Mamadou Sarr has suffered an injury setback, potentially affecting Chelsea’s transfer plans in the process.

Sarr was penciled in to start Chelsea’s pre-season friendly against Johor Darul Ta'zim on Sunday afternoon as Xabi Alonso picked a completely different XI from the 3-0 win over AC Milan 24 hours prior.

However, the Senegal international did not play a single minute as the Blues concluded their pre-season tour in Malaysia with a bad-tempered 3-3 draw.

Prior to kick-off at Sultan Ibrahim Stadium, it was revealed - without much of an explanation - that Sarr had been replaced in the starting XI by youngster Olutayo Subuloye.

There is yet to be an update on the 20-year-old, though Chelsea did issue a statement at the time the late change was announced.

"There has been a late change to the Chelsea starting XI against Johor Darul Ta'zim, with Olutayo Subuloye coming into the defence in place of Mamadou Sarr," the statement read.

"Sarr was initially included in the Blues' back line, but has now been replaced by Academy centre-back Subuloye."

If Sarr’s injury is serious then Chelsea could be forced to perform a transfer U-turn. revealed last month that Chelsea were keen for the defender to join a Premier League club on loan this summer, though the 20-year-old has several options elsewhere.

While the Blues had not ruled out keeping Sarr at the club for next season, Alonso was expected to hold talks with the former Strasbourg captain to determine his future.

Following Sarr’s withdrawal against JDT, a decision on his future will remain up in air until the severity of his knock is confirmed.

Chelsea suffered a second injury scare when Aaron Anselmino was forced off just before the half hour mark, while it was revealed after the game that Trevoh Chalobah had completed a move to Como in a deal worth €30million (£25.7m) plus up to €6m (£5.1m) in add-ons.

A statement reads: “Trevoh Chalobah has completed a permanent transfer to Como, bringing his time as a Chelsea player to an end after nearly two decades with the Blues.

“Everyone at Chelsea would like to thank Trev for his years of loyal service and wish him the very best in his next chapter in Italy.”