Nemanja Matic wants Oscar to remain positive after his penalty miss denied Chelsea three points against Watford.
With the score at 2-2, the defending Premier League champions were awarded a penalty when Valon Behrami felled substitute Eden Hazard inside the box with 10 minutes remaining.
However, Oscar, who converted from the spot against Sunderland last weekend, slipped as he made contact with the ball and sent his effort sailing over.
The Serbian - who conceded a first-half penalty for a needless handball - offered support to his team-mate, who he believes will be more successful next time.
"We had a penalty which we didn't score, we were unlucky. Oscar has to keep his head up because these things can happen. I'm sure he will score the next one," Matic told Sky Sports.
"We wanted to win today. It's not a good result for us, we are sad, we wanted three points. But this is football and you never know what will happen."
Chelsea face Manchester United on Monday and will be without Diego Costa - who scored both their goals in the draw with Watford - due to suspension, but Matic insists they will be ready.
"Manchester United are always very difficult and in three days we are playing two games," he added.
"We have to cope with that but we will be ready I am sure."