Is it possible to put the circled (-1, 1) on the same last row as the other values? Thank you for your help!!
\documentclass[a4paper]{article}
\usepackage{geometry} \geometry{a4paper, top=25mm, left=25mm, right=25mm, bottom=20mm, headsep=10mm, footskip=12mm}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{multirow,array}
\usepackage{arydshln}
\usepackage{tikz}
\dashlinegap=1pt
\usepackage{acronym}
\begin{document}
\begin{table}
\renewcommand\arraystretch{1.5}
\setlength{\tabcolsep}{4mm}
\begin{tabular}{*{5}{>{$}c<{$}}}
& & \multicolumn{2}{c}{Player II}& \\
& & \multicolumn{1}{c}{H} & \multicolumn{1}{c}{T} & \underset{s_1 \in S_1}{min} \, u(s_1, s_2) \\\cline{3-4}
\multirow{2}*{Player I}
& H & \multicolumn{1}{|c|}{1} & \multicolumn{1}{c|}{-1} &\multicolumn{1}{l}{-1} \\ \cline{3-4}
& T & \multicolumn{1}{|c|}{-1} & \multicolumn{1}{c|}{-1} &\multicolumn{1}{l}{-1} \\ \cline{3-4}
\multicolumn{1}{r@{}}{$\underset{s_2 \in S_2}{min} \, u(s_1, s_2)$} & & 1 &1 & \multicolumn{1}{l}{\tikz\node[draw,rounded corners=5pt,minimum width=1cm]{-1,1};}
\end{tabular}
\end{table}
\end{document}