Fitting coefficients on data so that the ratio of each variable is close to one - R

I have data that looks like this :

``````head(df)
player                 monday         tuesday  wednesday thursday       friday      saturday
<chr>                 <dbl>           <dbl>      <dbl>    <dbl>        <dbl>         <dbl>
1 Jack                     15              12         NA       6            NA            NA
2 John                     22              18         7        NA           NA            NA
3 Peter                    NA              NA         NA       NA           17.4          29.7
4 Jan                      NA              10         NA       4            NA            NA
5 Mike                     32              NA         NA       18.7         NA            NA
6 Jason                    NA              NA         NA       NA           11            14
``````

Every player performs at a different level. What I want to know is the effect that day has on performance as increase/decrease proportion of a base. So if we assume base Monday for Jack, Tuesday is 0.8 of Monday's performance.

My thought is that I need to fit coefficients for each day using least squares of the difference between 1 and the ratio of pairwise performance numbers. But I'm not sure how to do that.

Although maybe I'm over complicating, and there's a better way of tackling this.

Any help would be much appreciated.