Speed puts pressure on expert (4)
I believe the answer is:
pace
'speed' is the definition.
(pace is a kind of speed)
'pressure on expert' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'on' says to put letters next to each other.
'expert' becomes 'ace' (ace is a kind of expert).
'p'+'ace'='PACE'
'puts' is the link.
(Other definitions for pace that I've seen before include "Clip" , "politely expressing disagreement" , "Speed of a single step?" , "Lick" , "Gait" .)