It made me wonder that with 23 games remaining, how many runs will his absence cost the Orioles with his backups being Lew Ford and Xavier Avery. In doing so, I took Ford's and Avery runs above replacement (RAR) for offense and runs above average (RAA) for defense to determine how valuable they will be over the remainder of the season. You may wonder why one is replacement level and the other is against average. Both prominent metrics for evaluating a player holistically (b/rWAR and fWAR) compare players to a replacement level player (an abstract someone who should be available at AAA) who is defined as having a lower aptitude for hitting and an average aptitude for fielding.
Additionally, I compared those numbers to what Nick would be projected to do based on his season numbers. I also compared them to what Nick has done over the past 30 days (27 games). This should give us an idea how many runs losing Nick will cost the team.
Another assumption to be made here is that the defensive numbers are transferable from left field to right field for each player. Avery's arm (his major weakness) is adequate in left, but will be greatly tested in right field. Ford's arm is average in left field, but his range is below average. In other words, we should probably expect Ford to perform about the same and Avery worse than what Markakis is currently doing out there. If you use that qualitative approach, then defensive value should decrease about three runs leaving both players at seven runs in the whole compared to Markakis.
oRAR dRAA Proj. Difference Markakis Season 23 -9 3 Markakis last 30 6 -2 3 Ford -2 1 -1 -4 Avery 1 -2 -1 -4
An additional assumption is that these run values over the course of 17 games for Ford and 25 games for Avery are appropriate sample sizes to project performance forward. We know it takes about two years to get a decent evaluation of defense, so those numbers are probably rather useless. The offensive sample size is also pretty slight. It should be noted though that the overall expectation of their performance is replacement level. They deliver that performance in left field. The question is whether they can do that in right field.
This year's run environment put a win to every 9.285 runs produced. With that in mind, the range we have in lost performance (-4 to -7 runs) converts to -0.43 to -0.75 wins. This is not entirely convenient with the Orioles embroiled in such a tight race. An option could be for the team to try to improve themselves through a trade, but that player would not be eligible for the playoffs. In other words, it would be a costly trade, but perhaps a cost that might be needed to be made. However, there really are no good right fielders playing for teams out of the running on the market who will be free agents after the season.
So much depends on Lew Ford and Xavier Avery, but it probably does not depend as much as it feels.