This is their first meeting.
Overall results this year are stronger for Mertens. Her hard court results are also stronger although Cibulkova’s ROI is better for their last 10 matches on hard courts.
Mertens has come through the qualifying rounds. She did not loses a set in qualifying . In the main draw only Bertens has been able to take a set from her. She was underdog against Kasatkina in the second round but beat her in straight sets. She had a rest day yesterday when Zhang withdrew. That will have helped her energy levels.
Cibulkova came back from losing the opening set against Cornet in her first match. Last night against Pavlyuchenkova she was 1-3 down in the first set but broke back to 4-4. She then led 6-5 when someone in the crowd needed attention and the match was suspended for several minutes. When they eventually resumed Pavlyuchenkova’s concentration was affected and Cibulkova broke for the set. In the second set she took a 5-0 lead but Pavlyuchenkova broke her twice and also saved 3 match points. Pavlyuchenkova was serving for 5-5 and led 40-15 but Cibulkova broke her for the match.
I see some value on Mertens to take at least a set. Three sets look likely.
Lay Cibulkova if she breaks first and remove liability if she is then broken.
Update: Cibulkova won in 2 sets. Mertens was ahead by a break in the second set but her serve was poor and she couldn’t hold on.