But we do know for sure that Irish teams did enter the FA Cup from 1886-1890.
1886-87- The first Irish club to play in the FA Cup were Cliftonville. After a 2-2 draw away to Blackburn Park Road they won the replay 7-2.
In the second round they traveled to Great Lever. A 3-1 win saw them rewarded with a home draw in the 3rd round but Scotland's Partick Thistle proved too strong for them, running out 11-0 winners.
CliftonvilleIn the 1887-88 season 2 Irish sides entered, although Cliftonville didn't play, presenting opponents Church with a walk over in the first round.
Distillery lost 2-1 to Blackburn Park Road, but progressed to the 2nd round when the Blackburn outfit were disqualified. In the next round Distillery hosted Witton, who beat them 4-2.
1888-89 saw the introduction of qualifying rounds. In the 1st qualifying round Ulster received a walkover from Everton.
In the 2nd qualifying round Ulster hosted fellow Irish side Linfield, who ran out 7-1 winners, whilst Cliftonville beat Belfast YMCA 5-0.
In the 3rd qualifying round Cliftonville benefited from a walkover at the expense of Liverpool Stanley, Linfield enjoying a 4-0 home win over Bolton Wanderers.
In the 4th qualifying round the two surviving Irish teams were drawn together, and it took 3 matches to separate them. Following two 3-3 draws Linfield won the tie 7-0 on Christmas day.
In the 1st round proper Linfield drew 2-2 with Nottingham Forest (away) but withdrew before the replay.
In 1889-90 Distillery received a bye in the 2nd qualifying round, and a walk over against Belfast YMCA in the 3rd qualifying round. Linfield entered in the 3rd qualifying round with a walk over against Belfast North End.
Linfield and Distillery played each other in the 4th qualifying round- Distillery won a replay 5-3 following a 3-3 draw.
Distillery's reward was an away tie with Bolton Wanderers, which the English club won 10-2.