Barnsley drew 1-1 at Forest last Saturday and lost 2-1 to Sheffield United on Tuesday, with Jamal Campbell-Ryce missing a penalty in each fixture.
The Tykes had numerous other scoring chances and Davey has called on his troops to show more composure against Watford on Saturday and in the Easter Monday meeting with Swansea at Oakwell.
"We have to make sure we take our opportunities when they come along," Davey told the club's official website. "Every game is going to be tight and nervous now. We have to make sure we capitalise on those chances we get.
"Everybody has a shot this weekend and it is tough to keep sending the same team out every game when you have so many matches. We need to get three points as soon as possible and that starts at Watford. We have to make sure we approach both matches in the right manner and get a win on the board as soon as possible."