It seems that I encountered an issue retrieving the player overviews for both Christian McCaffrey and James Cook, and I couldn't find specific recent data on them either. However, I can provide some general insights based on their typical performance and roles.

Christian McCaffrey

• Role: McCaffrey is often considered one of the top running backs in the league due to his dual-threat ability as both a runner and a receiver. He typically sees a high volume of touches and is heavily involved in the passing game.
• Performance: Historically, when healthy, McCaffrey has been a top fantasy performer, often finishing as a top-5 running back in PPR formats.

James Cook

• Role: Cook has been emerging as a key player for the Buffalo Bills, especially in a high-powered offense. His role has been growing, and he has shown the ability to contribute both on the ground and through the air.
• Performance: While Cook may not have the same track record as McCaffrey, he has been effective in his opportunities and can be a solid flex option, especially in favorable matchups.

Recommendation

Given McCaffrey's established track record and his potential for high volume, he is generally the safer start if he is healthy. However, if there are any concerns about McCaffrey's health or matchup, Cook could be a viable alternative, especially if he has a favorable matchup.

Final Thoughts

Without the latest statistics or injury updates, I recommend checking the latest news on both players before making your decision. If McCaffrey is healthy and starting, he is likely the better option. If there are any doubts about his playing time or effectiveness, consider starting Cook instead.