Fletcher, who joined West Brom in February 2015 on a free transfer after leaving Manchester United, started the Premier League encounter at the Boleyn Ground and played for the entire 90 minutes.
Crooks was impressed with the shift put in by the 31-year-old Scotland international midfielder in the 1-1 draw.
The BBC pundit, though, observed that Fletcher’s midfield partner Claudio Yacob is often unpredictable.
“Against West Ham the former Manchester United player and Scotland captain was the Baggies' steadying influence, particularly for his midfield partner Claudio Yacob, who is often unpredictable but now looks as steady as a rock too,” Crooks wrote on BBC Sport. “Football teams can't go wrong with players like Darren Fletcher playing in them."
West Brom are 13th in the Premier League table at the moment with 18 points from 14 matches, eight points above the relegation zone.
Fletcher has created seven chances in 14 league appearances for the Baggies so far this season.
The former United midfielder has a pass accuracy of 82% and a shot accuracy of 33%, and has won 18 headers, 13 dribbles and 18 tackles.
Meanwhile, Argentine midfielder Yacob has created five chances in 14 Premier League matches this campaign.
The 28-year-old has a pass accuracy of 78%, and has won 21 headers, four dribbles and 28 tackles.