The 22-year-old, who joined the Czech side from Bohemians 1905, has been a pale shadow of himself this season.
The Ghanaian struggled in the first half of the season where he scored five goals in 18 appearances.
And the former Ghana Under-20 striker admits he is unsure what has hit him but vows to bounce back.
"I can't tell you why I don't score so many goals anymore," admits the Ghanaian striker, who hopes to fix everything in the spring.
"If you ask me why I didn't score goals on my start, I won't tell you a clear reason. I didn't have good form, I didn't play like I did in my first six months at the club.Sometimes I watch videos with my first-six-year performances in Sparta and I think, 'What happened to me?' I don't know the answer, but I know I'm always trying to do everything I can to play my best," the grown-up player confided in front of the club's television camera.
Sparta have lost all their three preparatory matches in Spain.
The Ghanaian further added: "I don't think the one who plays around me has a big influence on my game.Everyone has their own individual qualities, and no matter who they're playing with, everyone should be able to show them off... But of course, when Nico (Stanciu) was here, we had a close relationship and we were able to bring it to the field.Now Bořek's here, and he's a phenomenal player.If he plays and he's healthy, he can be absolutely top and I can benefit from it because he's the kind of player who wants to play forward all the time," said sparta' 22-year-old striker.
The Czech side have returned home where they welcome Liberec at home on Saturday.