Admittedly Miguel might be older, have a smaller range, and have a weaker arm compared to "real" ML shortstops, but the Reds need some additional offense.
As per another thread: Cairo has been in 64 big league games at SS (although mostly late 1990's to mid 2000's). I bet that he still can make the routine plays at least.
At .288/.356/.407, Cairo's 1 or 2 hits per game, and an extra base knock per 14-15 AB, should help turn the lineup over more frequently and produce some additional runs scored and RBI.
He probably can not play more than 4-5 days a week and probably would need replaced by Janish late in the game with a lead -- but the Reds need to FIRST GET THAT LEAD!!