Run-time error 1004 - Unable to get the match property of WorksheetFucntion lass

I keep getting a runtime error but I do not know why. It is giving me a Run-time error 1004 "Unable to get the Match property of the WorksheetFunction class." It highlights a variable that I try to define. I copy/pasted the match criteria, so I know it is accurate.

Anyone have an idea of what's wrong?

Dim i, i2, i3, i4, LR, lRow As Long, rngData As Range


    i1 = Application.WorksheetFunction.Match("MGR_NAME", Range("1:1"), 0)

the name of the worksheet is called ("Mod")

Ok cool. If I had to declare a bunch of i variable from the same sheet, would it make more sense to use a "With...End With" statement?

Just to define them all at once:

Dim i, i2, i3, i4, LR As Long, rngData As Range

With Worksheets("MOD").Activate

    Set rngData = Range("A1").CurrentRegion

    i1 = Application.WorksheetFunction.Match("MGR_NAME", Range("1:1"), 0)
    i2 = Application.WorksheetFunction.Match("7060", Range("1:1"), 0)
    i3 = Application.WorksheetFunction.Match("7194", Range("1:1"), 0)
    i4 = Application.WorksheetFunction.Match("WORKOUT_TYPE", Range("1:1"), 0)

End With

okkk so I'll just get rid of the .activate. The rngData was for something else that I was trying, but it doesnt seem necessary anymore. Thank you for your help.