Javier Hernandez has warned Chelsea that his fellow Manchester United forward Wayne Rooney is motivated and will cause an "extra problem" to them.
The England international's season has been a mixed one, which involved him threatening to quit the Old Trafford outfit before committing his future to the club by signing a new contract.
The 25-year-old was also in the tabloids due to allegations concerning his personal life, while his form shown on the pitch appeared to have deserted him as well.
However, the former Everton man scored a hat-trick against West Ham on Saturday, and the Mexican believes that his team-mate is fired up to avenge the defeat they suffered against the Blues last month.
"Wayne is in sensational form and this is an extra problem for Chelsea," Hernandez told The Sun.
"He really wants to score in the London leg and he is super motivated for this one.
"The manager wants us to create a lot of chances in the away leg and make sure we score so we can tackle the return leg with more options.
"That defeat by Chelsea in the league wasn't just. Our win over West Ham has improved our morale - it means we are much better placed to win the league."
Hernandez also predicted that the team with the better strike force will win the double-header between the two sides.
Blues boss Carlo Ancelotti had in the past expressed a belief that his attacking line is the best in Europe, but the 22-year-old disagrees.
"The side with the best set of forwards will reach the semi-finals. Chelsea have an excellent attack, but our forwards are better," he said.
"Mentally we are very calm about facing Chelsea in Europe. We want to strike a blow at Stamford Bridge."