Nah, he’s shit. Here are his stats from premierleague.com for his 47 appearances. Some will be crappy last few minutes of a game but you’d expect better from a player in a top side. He loses more duels and tackles than he wins.
Defence
Tackles 69
Tackle success % 42%
Blocked shots 15
Interceptions 25
Clearances 17
Headed Clearance 6
Recoveries 208
Duels won 165
Duels lost 184
Successful 50/50s 51
Aerial battles won 20
Aerial battles lost 33
Errors leading to goal 0
If you want to go all scientific on us, you will need stats from the other midfielders as well, and also attacking stats as all players do both.
I wouldn't start Keita in this game though, as he is just back from injury.