The Chelsea manager revealed that Christopher Knunku picked up a hip problem while in training earlier in the week.
After a frustrating first half for the Blues, they sprung to life after the break as they put four goals past Preston to progress to the next round of the FA Cup.
Armando Broja started up front in Nicolas Jackson’s absence and gave his side the lead after 58 minutes.
The goals then came thick and fast, with Thiago Silva and Raheem Sterling scoring within three minutes before Enzo Fernandes grabbed the fourth and final in the 85th minute.
Summer signing Knunku was absent from the squad with Mauricio Pochettino revealing in his post-match press conference that he picked up a hip issue.
‘He wasn’t involved because he suffered after training a problem in his hip,’ he said via the Daily Mail.
‘We need to see if he can be ready for the next few games.’
The French forward suffered a knee injury in pre-season and only made his return last month with another issue the last thing he needs.
Chelsea’s face Middlesbrough in the first leg of their Carabao Cup semi-final on Tuesday before they welcome London rivals Fulham in the Premier League next weekend.