Chelsea head coach Maurizio Sarri believes it would be "impossible" to replace Eden Hazard amid growing links with LaLiga giants Real Madrid.
Hazard produced a memorable display with two goals in Chelsea's 2-0 Premier League victory over West Ham on Monday.
The rumoured Madrid target opened the scoring via a sensational solo run before sealing the points in the closing stages as Chelsea moved up to third in the table.
As speculation mounts over Hazard's future at Stamford Bridge, Sarri conceded the Belgium international is irreplaceable.
"I think a big performance from the team, [Eden] Hazard, of course, played a wonderful match," Sarri said post-match.
"He scored an incredible goal, the first goal is really an incredible goal. When Hazard is able to play like he has in the last two matches for the team, of course, it's easier.
"From the technical point of view, no [cannot afford to lose Hazard], not at the moment.
"Also because it is impossible to find another Hazard. At the moment there isn't another Hazard, the level is so high."
Hazard has scored 19 goals in all competitions for Chelsea this season, with 16 of those coming in the Premier League.