Watford boss, Walter Mazzarri, admitted he has been impressed with the substitute appearances of Isaac Success but that he may not be a straight swap for Odion Ighalo.
Success joined the Hornets for a then club-record fee in the summer and the 20-year-old was the one bright spark when he came on at Burnley on Monday night.
In contrast, his Nigerian team-mate, Ighalo, has struggled to make the same impact at the start of this season as he did to the last campaign.
The 27-year-old has started every game so far but found the back of the net just once with a deflected effort at West Ham.
A number of Hornets fans have been clamouring for Success to be given the chance to start with Troy Deeney up top, but Mazzarri explains it may not be a simple straight swap.
He said: “Success is a player that didn’t do the whole preparation with the team in the summer.
“There are many things that we have to consider. We have to consider as well if he has the 90 minutes in the leg or not.
“We have three substitutes and we have to see who starts and who will come as a substitute.
“I agree that Success is a player that has a lot of quality and when he has come in as a substitute he has always had a great impact on the game.
“Ighalo is a striker but can play in many different positions. He can play as a second striker and as a winger as he did against West Ham.
“Success at this moment is more a winger/striker.
“So he can start on the left and go into the box and shoot with his right. While Ighalo can play in much more different positions than Success can in this moment.”