The 1890 Portland team photo was discussed previously in a different thread:
(
https://forums.ootpdevelopments.com/...nd#post4266974)
I'm bringing the discussion here and summarizing some of the findings across the various posts. There are two key matches that set who is likely in the photo: the manager, pictured in street clothes, and the player third from the left in the back row. The former appears to be Henry Harris, who came onto the club in mid-May, replacing Dick Dwyer. Harris left the club towards the end of August. The latter appears to be Bill Hassamaer, whose first game was June 19. That sets the date for the photo sometime between these two dates. A comparison of the possible managers is shown below. The nose and the eye (IMO) are a better match with Harris. (The photo of Dwyer, on the left, is from a team photo of the Omaha Union Pacific club of late 1884 or early 1885. It should be noted that the cast of possible players in the Portland team photo changes almost completely if the manager pictured is Dwyer.) The match for Hassamaer is from Baseball-Reference.
Added 9/23/2021:
Summarizing the matches below and previously, the proposed identifications are
Back row: Harry Hulin, Unidentified 3, Bill Hassamaer, George Rhue, Jiggs Parrott, Bill Whitrock
Middle row: Unidentified 1, Unidentified 2, Henry Harris (Manager), Tom Parrott, Harry O'Day
Front Row: Frank Buchtel, Pat Whitaker
Candidates for remaining unknown players: David Levy, Jack G. Munday, Gus Land, Joseph Schachern
Updated 9/2/2022:
A photo of Jack Munday is available on pg 6 of this thread. I think it is a match for the second person in the back row (Unidentified 3). Gus Land was 22 at the time of the photo (pg 8). I think he is Unidentified 2, the second person in the second row (next to the manager). That puts Joe Schachern as the first person sitting on the bench in the second row (Unidentified 1).