Yes, they can but temporary foreign worker (TFW) has to be in Canada and working here under a positive Labour Market Impact Assessment (LIMA). If they are working under LIMA then an employer can offer an employee a permanent job to back up his/her application for permanent residence. The TFW still have to fill online application for Express Entry for permanent residence and have to mention their job offer information.
Once the candidate has a valid job offer and it is supported by LIMA, it will give candidate enough additional points which provide them invitation to apply for next draw of candidates.